diff --git a/api/apps/document_app.py b/api/apps/document_app.py
index fb6f9fdd4..934da374c 100644
--- a/api/apps/document_app.py
+++ b/api/apps/document_app.py
@@ -42,7 +42,8 @@ from api.utils.api_utils import (
     server_error_response,
     validate_request,
 )
-from api.utils.file_utils import filename_type, get_project_base_directory, thumbnail
+from api.utils.file_utils import filename_type, thumbnail
+from common.file_utils import get_project_base_directory
 from api.utils.web_utils import CONTENT_TYPE_MAP, html2pdf, is_valid_url
 from deepdoc.parser.html_parser import RAGFlowHtmlParser
 from rag.nlp import search, rag_tokenizer
diff --git a/api/db/init_data.py b/api/db/init_data.py
index 39b87d06f..78ef6cfc9 100644
--- a/api/db/init_data.py
+++ b/api/db/init_data.py
@@ -30,7 +30,7 @@ from api.db.services.tenant_llm_service import LLMFactoriesService, TenantLLMSer
 from api.db.services.llm_service import LLMService, LLMBundle, get_init_tenant_llm
 from api.db.services.user_service import TenantService, UserTenantService
 from api import settings
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from api.common.base64 import encode_to_base64
 
 
diff --git a/api/ragflow_server.py b/api/ragflow_server.py
index fb49f3d8b..8ce391649 100644
--- a/api/ragflow_server.py
+++ b/api/ragflow_server.py
@@ -36,7 +36,7 @@ from api import settings
 from api.apps import app, smtp_mail_server
 from api.db.runtime_config import RuntimeConfig
 from api.db.services.document_service import DocumentService
-from api import utils
+from common.file_utils import get_project_base_directory
 
 from api.db.db_models import init_database_tables as init_web_db
 from api.db.init_data import init_web_data
@@ -88,7 +88,7 @@ if __name__ == '__main__':
         f'RAGFlow version: {get_ragflow_version()}'
     )
     logging.info(
-        f'project base: {utils.file_utils.get_project_base_directory()}'
+        f'project base: {get_project_base_directory()}'
     )
     show_configs()
     settings.init_settings()
diff --git a/api/settings.py b/api/settings.py
index c8573bf29..592753eb2 100644
--- a/api/settings.py
+++ b/api/settings.py
@@ -25,7 +25,7 @@ import rag.utils.infinity_conn
 import rag.utils.opensearch_conn
 from api.constants import RAG_FLOW_SERVICE_NAME
 from api.utils.configs import decrypt_database_config, get_base_config
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from rag.nlp import search
 
 LLM = None
diff --git a/api/utils/configs.py b/api/utils/configs.py
index 48e492246..c586d9091 100644
--- a/api/utils/configs.py
+++ b/api/utils/configs.py
@@ -23,6 +23,7 @@ import pickle
 import importlib
 
 from api.utils import file_utils
+from common.file_utils import get_project_base_directory
 from filelock import FileLock
 from api.utils.common import bytes_to_string, string_to_bytes
 from api.constants import SERVICE_CONF
@@ -30,7 +31,7 @@ from api.constants import SERVICE_CONF
 
 def conf_realpath(conf_name):
     conf_path = f"conf/{conf_name}"
-    return os.path.join(file_utils.get_project_base_directory(), conf_path)
+    return os.path.join(get_project_base_directory(), conf_path)
 
 
 def read_config(conf_name=SERVICE_CONF):
@@ -129,8 +130,7 @@ def decrypt_database_config(
 def update_config(key, value, conf_name=SERVICE_CONF):
     conf_path = conf_realpath(conf_name=conf_name)
     if not os.path.isabs(conf_path):
-        conf_path = os.path.join(
-            file_utils.get_project_base_directory(), conf_path)
+        conf_path = os.path.join(get_project_base_directory(), conf_path)
 
     with FileLock(os.path.join(os.path.dirname(conf_path), ".lock")):
         config = file_utils.load_yaml_conf(conf_path=conf_path) or {}
diff --git a/api/utils/crypt.py b/api/utils/crypt.py
index eb922a886..174ca3568 100644
--- a/api/utils/crypt.py
+++ b/api/utils/crypt.py
@@ -19,14 +19,14 @@ import os
 import sys
 from Cryptodome.PublicKey import RSA
 from Cryptodome.Cipher import PKCS1_v1_5 as Cipher_pkcs1_v1_5
-from api.utils import file_utils
+from common.file_utils import get_project_base_directory
 
 
 def crypt(line):
     """
     decrypt(crypt(input_string)) == base64(input_string), which frontend and admin_client use.
     """
-    file_path = os.path.join(file_utils.get_project_base_directory(), "conf", "public.pem")
+    file_path = os.path.join(get_project_base_directory(), "conf", "public.pem")
     rsa_key = RSA.importKey(open(file_path).read(), "Welcome")
     cipher = Cipher_pkcs1_v1_5.new(rsa_key)
     password_base64 = base64.b64encode(line.encode('utf-8')).decode("utf-8")
@@ -35,7 +35,7 @@ def crypt(line):
 
 
 def decrypt(line):
-    file_path = os.path.join(file_utils.get_project_base_directory(), "conf", "private.pem")
+    file_path = os.path.join(get_project_base_directory(), "conf", "private.pem")
     rsa_key = RSA.importKey(open(file_path).read(), "Welcome")
     cipher = Cipher_pkcs1_v1_5.new(rsa_key)
     return cipher.decrypt(base64.b64decode(line), "Fail to decrypt password!").decode('utf-8')
@@ -50,7 +50,7 @@ def decrypt2(crypt_text):
         hex_fixed = '00' + decode_data.hex()
         decode_data = b16decode(hex_fixed.upper())
 
-    file_path = os.path.join(file_utils.get_project_base_directory(), "conf", "private.pem")
+    file_path = os.path.join(get_project_base_directory(), "conf", "private.pem")
     pem = open(file_path).read()
     rsa_key = RSA.importKey(pem, "Welcome")
     cipher = Cipher_PKCS1_v1_5.new(rsa_key)
diff --git a/api/utils/file_utils.py b/api/utils/file_utils.py
index 999a1147d..8eb84dcd2 100644
--- a/api/utils/file_utils.py
+++ b/api/utils/file_utils.py
@@ -43,6 +43,7 @@ from ruamel.yaml import YAML
 # Local imports
 from api.constants import IMG_BASE64_PREFIX
 from api.db import FileType
+from common.file_utils import get_project_base_directory
 
 PROJECT_BASE = os.getenv("RAG_PROJECT_BASE") or os.getenv("RAG_DEPLOY_BASE")
 
@@ -51,21 +52,6 @@ if LOCK_KEY_pdfplumber not in sys.modules:
     sys.modules[LOCK_KEY_pdfplumber] = threading.Lock()
 
 
-def get_project_base_directory(*args):
-    global PROJECT_BASE
-    if PROJECT_BASE is None:
-        PROJECT_BASE = os.path.abspath(
-            os.path.join(
-                os.path.dirname(os.path.realpath(__file__)),
-                os.pardir,
-                os.pardir,
-            )
-        )
-
-    if args:
-        return os.path.join(PROJECT_BASE, *args)
-    return PROJECT_BASE
-
 @cached(cache=LRUCache(maxsize=10))
 def load_json_conf(conf_path):
     if os.path.isabs(conf_path):
diff --git a/api/utils/log_utils.py b/api/utils/log_utils.py
index 0a4840e79..0348f9e09 100644
--- a/api/utils/log_utils.py
+++ b/api/utils/log_utils.py
@@ -17,19 +17,10 @@ import os
 import os.path
 import logging
 from logging.handlers import RotatingFileHandler
+from common.file_utils import get_project_base_directory
 
 initialized_root_logger = False
 
-def get_project_base_directory():
-    PROJECT_BASE = os.path.abspath(
-        os.path.join(
-            os.path.dirname(os.path.realpath(__file__)),
-            os.pardir,
-            os.pardir,
-        )
-    )
-    return PROJECT_BASE
-
 def init_root_logger(logfile_basename: str, log_format: str = "%(asctime)-15s %(levelname)-8s %(process)d %(message)s"):
     global initialized_root_logger
     if initialized_root_logger:
diff --git a/common/file_utils.py b/common/file_utils.py
new file mode 100644
index 000000000..6b07bf646
--- /dev/null
+++ b/common/file_utils.py
@@ -0,0 +1,33 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+import os
+
+PROJECT_BASE = os.getenv("RAG_PROJECT_BASE") or os.getenv("RAG_DEPLOY_BASE")
+
+def get_project_base_directory(*args):
+    global PROJECT_BASE
+    if PROJECT_BASE is None:
+        PROJECT_BASE = os.path.abspath(
+            os.path.join(
+                os.path.dirname(os.path.realpath(__file__)),
+                os.pardir,
+            )
+        )
+
+    if args:
+        return os.path.join(PROJECT_BASE, *args)
+    return PROJECT_BASE
diff --git a/deepdoc/parser/pdf_parser.py b/deepdoc/parser/pdf_parser.py
index c9f2f34ca..dba55bb13 100644
--- a/deepdoc/parser/pdf_parser.py
+++ b/deepdoc/parser/pdf_parser.py
@@ -34,7 +34,7 @@ from huggingface_hub import snapshot_download
 from PIL import Image
 from pypdf import PdfReader as pdf2_read
 
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from api.utils.common import pip_install_torch
 from deepdoc.vision import OCR, AscendLayoutRecognizer, LayoutRecognizer, Recognizer, TableStructureRecognizer
 from rag.app.picture import vision_llm_chunk as picture_vision_llm_chunk
diff --git a/deepdoc/vision/layout_recognizer.py b/deepdoc/vision/layout_recognizer.py
index 9cd0b5a5d..8068cbc07 100644
--- a/deepdoc/vision/layout_recognizer.py
+++ b/deepdoc/vision/layout_recognizer.py
@@ -25,7 +25,7 @@ import cv2
 import numpy as np
 from huggingface_hub import snapshot_download
 
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from deepdoc.vision import Recognizer
 from deepdoc.vision.operators import nms
 
diff --git a/deepdoc/vision/ocr.py b/deepdoc/vision/ocr.py
index 1a99e6ce0..4c4831d7c 100644
--- a/deepdoc/vision/ocr.py
+++ b/deepdoc/vision/ocr.py
@@ -21,7 +21,7 @@ import os
 
 from huggingface_hub import snapshot_download
 
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from api.utils.common import pip_install_torch
 from rag.settings import PARALLEL_DEVICES
 from .operators import *  # noqa: F403
diff --git a/deepdoc/vision/recognizer.py b/deepdoc/vision/recognizer.py
index 65995a579..af259a384 100644
--- a/deepdoc/vision/recognizer.py
+++ b/deepdoc/vision/recognizer.py
@@ -22,7 +22,7 @@ import cv2
 from functools import cmp_to_key
 
 
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from .operators import *  # noqa: F403
 from .operators import preprocess
 from . import operators
diff --git a/deepdoc/vision/table_structure_recognizer.py b/deepdoc/vision/table_structure_recognizer.py
index 34b988e9a..cf1c79db1 100644
--- a/deepdoc/vision/table_structure_recognizer.py
+++ b/deepdoc/vision/table_structure_recognizer.py
@@ -21,7 +21,7 @@ from collections import Counter
 import numpy as np
 from huggingface_hub import snapshot_download
 
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from rag.nlp import rag_tokenizer
 
 from .recognizer import Recognizer
diff --git a/rag/nlp/rag_tokenizer.py b/rag/nlp/rag_tokenizer.py
index c3394971e..3c4b97833 100644
--- a/rag/nlp/rag_tokenizer.py
+++ b/rag/nlp/rag_tokenizer.py
@@ -25,7 +25,7 @@ import sys
 from hanziconv import HanziConv
 from nltk import word_tokenize
 from nltk.stem import PorterStemmer, WordNetLemmatizer
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 
 
 class RagTokenizer:
diff --git a/rag/nlp/synonym.py b/rag/nlp/synonym.py
index b28560ce1..0956ee8e8 100644
--- a/rag/nlp/synonym.py
+++ b/rag/nlp/synonym.py
@@ -20,7 +20,7 @@ import os
 import time
 import re
 from nltk.corpus import wordnet
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 
 
 class Dealer:
diff --git a/rag/nlp/term_weight.py b/rag/nlp/term_weight.py
index 33ee62660..392117c18 100644
--- a/rag/nlp/term_weight.py
+++ b/rag/nlp/term_weight.py
@@ -21,7 +21,7 @@ import re
 import os
 import numpy as np
 from rag.nlp import rag_tokenizer
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 
 
 class Dealer:
diff --git a/rag/settings.py b/rag/settings.py
index 6c2017dc1..6167c08ae 100644
--- a/rag/settings.py
+++ b/rag/settings.py
@@ -16,7 +16,7 @@
 import os
 import logging
 from api.utils.configs import get_base_config, decrypt_database_config
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from api.utils.common import pip_install_torch
 
 # Server
diff --git a/rag/svr/task_executor.py b/rag/svr/task_executor.py
index 7bc577c63..8a0d464ba 100644
--- a/rag/svr/task_executor.py
+++ b/rag/svr/task_executor.py
@@ -28,7 +28,8 @@ from api.db.services.knowledgebase_service import KnowledgebaseService
 from api.db.services.pipeline_operation_log_service import PipelineOperationLogService
 from api.utils.api_utils import timeout
 from api.utils.base64_image import image2id
-from api.utils.log_utils import init_root_logger, get_project_base_directory
+from api.utils.log_utils import init_root_logger
+from common.file_utils import get_project_base_directory
 from api.utils.configs import show_configs
 from graphrag.general.index import run_graphrag_for_kb
 from graphrag.utils import get_llm_cache, set_llm_cache, get_tags_from_cache, set_tags_to_cache
diff --git a/rag/utils/__init__.py b/rag/utils/__init__.py
index f3a696318..64db543b1 100644
--- a/rag/utils/__init__.py
+++ b/rag/utils/__init__.py
@@ -17,7 +17,7 @@
 import os
 import tiktoken
 
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 
 tiktoken_cache_dir = get_project_base_directory()
 os.environ["TIKTOKEN_CACHE_DIR"] = tiktoken_cache_dir
diff --git a/rag/utils/es_conn.py b/rag/utils/es_conn.py
index e662428ba..e2ce8c9ed 100644
--- a/rag/utils/es_conn.py
+++ b/rag/utils/es_conn.py
@@ -27,7 +27,7 @@ from elastic_transport import ConnectionTimeout
 from rag import settings
 from rag.settings import TAG_FLD, PAGERANK_FLD
 from common.decorator import singleton
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from api.utils.common import convert_bytes
 from rag.utils.doc_store_conn import DocStoreConnection, MatchExpr, OrderByExpr, MatchTextExpr, MatchDenseExpr, \
     FusionExpr
diff --git a/rag/utils/infinity_conn.py b/rag/utils/infinity_conn.py
index 1d6dbd091..9a92c8e86 100644
--- a/rag/utils/infinity_conn.py
+++ b/rag/utils/infinity_conn.py
@@ -29,7 +29,7 @@ from rag import settings
 from rag.settings import PAGERANK_FLD, TAG_FLD
 from common.decorator import singleton
 import pandas as pd
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from rag.nlp import is_english
 
 from rag.utils.doc_store_conn import (
diff --git a/rag/utils/opensearch_conn.py b/rag/utils/opensearch_conn.py
index 3c2cf376b..5c51be52f 100644
--- a/rag/utils/opensearch_conn.py
+++ b/rag/utils/opensearch_conn.py
@@ -27,7 +27,7 @@ from opensearchpy import ConnectionTimeout
 from rag import settings
 from rag.settings import TAG_FLD, PAGERANK_FLD
 from common.decorator import singleton
-from api.utils.file_utils import get_project_base_directory
+from common.file_utils import get_project_base_directory
 from rag.utils.doc_store_conn import DocStoreConnection, MatchExpr, OrderByExpr, MatchTextExpr, MatchDenseExpr, \
     FusionExpr
 from rag.nlp import is_english, rag_tokenizer
diff --git a/test/unit_test/common/test_file_utils.py b/test/unit_test/common/test_file_utils.py
new file mode 100644
index 000000000..616312cde
--- /dev/null
+++ b/test/unit_test/common/test_file_utils.py
@@ -0,0 +1,123 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+import os
+import pytest
+from unittest.mock import patch
+from common import file_utils
+from common.file_utils import get_project_base_directory
+
+
+class TestGetProjectBaseDirectory:
+    """Test cases for get_project_base_directory function"""
+
+    def test_returns_project_base_when_no_args(self):
+        """Test that function returns project base directory when no arguments provided"""
+        result = get_project_base_directory()
+
+        assert result is not None
+        assert isinstance(result, str)
+        assert os.path.isabs(result)  # Should return absolute path
+
+    def test_returns_path_with_single_argument(self):
+        """Test that function joins project base with single additional path component"""
+        result = get_project_base_directory("subfolder")
+
+        assert result is not None
+        assert "subfolder" in result
+        assert result.endswith("subfolder")
+
+    def test_returns_path_with_multiple_arguments(self):
+        """Test that function joins project base with multiple path components"""
+        result = get_project_base_directory("folder1", "folder2", "file.txt")
+
+        assert result is not None
+        assert "folder1" in result
+        assert "folder2" in result
+        assert "file.txt" in result
+        assert os.path.basename(result) == "file.txt"
+
+    def test_uses_environment_variable_when_available(self):
+        """Test that function uses RAG_PROJECT_BASE environment variable when set"""
+        test_path = "/custom/project/path"
+
+        file_utils.PROJECT_BASE = test_path
+
+        result = get_project_base_directory()
+        assert result == test_path
+
+    def test_calculates_default_path_when_no_env_vars(self):
+        """Test that function calculates default path when no environment variables are set"""
+        with patch.dict(os.environ, {}, clear=True):  # Clear all environment variables
+            # Reset the global variable to force re-initialization
+
+            result = get_project_base_directory()
+
+            # Should return a valid absolute path
+            assert result is not None
+            assert os.path.isabs(result)
+            assert os.path.basename(result) != ""  # Should not be root directory
+
+    def test_caches_project_base_value(self):
+        """Test that PROJECT_BASE is cached after first calculation"""
+        # Reset the global variable
+
+        # First call should calculate the value
+        first_result = get_project_base_directory()
+
+        # Store the current value
+        cached_value = file_utils.PROJECT_BASE
+
+        # Second call should use cached value
+        second_result = get_project_base_directory()
+
+        assert first_result == second_result
+        assert file_utils.PROJECT_BASE == cached_value
+
+    def test_path_components_joined_correctly(self):
+        """Test that path components are properly joined with the base directory"""
+        base_path = get_project_base_directory()
+        expected_path = os.path.join(base_path, "data", "files", "document.txt")
+
+        result = get_project_base_directory("data", "files", "document.txt")
+
+        assert result == expected_path
+
+    def test_handles_empty_string_arguments(self):
+        """Test that function handles empty string arguments correctly"""
+        result = get_project_base_directory("")
+
+        # Should still return a valid path (base directory)
+        assert result is not None
+        assert os.path.isabs(result)
+
+
+# Parameterized tests for different path combinations
+@pytest.mark.parametrize("path_args,expected_suffix", [
+    ((), ""),  # No additional arguments
+    (("src",), "src"),
+    (("data", "models"), os.path.join("data", "models")),
+    (("config", "app", "settings.json"), os.path.join("config", "app", "settings.json")),
+])
+def test_various_path_combinations(path_args, expected_suffix):
+    """Test various combinations of path arguments"""
+    base_path = get_project_base_directory()
+    result = get_project_base_directory(*path_args)
+
+    if expected_suffix:
+        assert result.endswith(expected_suffix)
+    else:
+        assert result == base_path