diff --git a/agent/tools/retrieval.py b/agent/tools/retrieval.py
index f024c42fa..77a39b731 100644
--- a/agent/tools/retrieval.py
+++ b/agent/tools/retrieval.py
@@ -193,7 +193,7 @@ class Retrieval(ToolBase, ABC):
 
             if self._param.toc_enhance:
                 chat_mdl = LLMBundle(self._canvas._tenant_id, LLMType.CHAT)
-                cks = settings.retriever.retrieval_by_toc(query, kbinfos["chunks"], [kb.tenant_id for kb in kbs],
+                cks = await settings.retriever.retrieval_by_toc(query, kbinfos["chunks"], [kb.tenant_id for kb in kbs],
                                                           chat_mdl, self._param.top_n)
                 if self.check_if_canceled("Retrieval processing"):
                     return
diff --git a/api/apps/sdk/doc.py b/api/apps/sdk/doc.py
index db8a97b68..d341cea55 100644
--- a/api/apps/sdk/doc.py
+++ b/api/apps/sdk/doc.py
@@ -1575,7 +1575,7 @@ async def retrieval_test(tenant_id):
         )
         if toc_enhance:
             chat_mdl = LLMBundle(kb.tenant_id, LLMType.CHAT)
-            cks = settings.retriever.retrieval_by_toc(question, ranks["chunks"], tenant_ids, chat_mdl, size)
+            cks = await settings.retriever.retrieval_by_toc(question, ranks["chunks"], tenant_ids, chat_mdl, size)
             if cks:
                 ranks["chunks"] = cks
         if use_kg:
diff --git a/api/db/services/dialog_service.py b/api/db/services/dialog_service.py
index 33b50730f..83f1bb4fa 100644
--- a/api/db/services/dialog_service.py
+++ b/api/db/services/dialog_service.py
@@ -411,7 +411,7 @@ async def async_chat(dialog, messages, stream=True, **kwargs):
                     rank_feature=label_question(" ".join(questions), kbs),
                 )
                 if prompt_config.get("toc_enhance"):
-                    cks = retriever.retrieval_by_toc(" ".join(questions), kbinfos["chunks"], tenant_ids, chat_mdl, dialog.top_n)
+                    cks = await retriever.retrieval_by_toc(" ".join(questions), kbinfos["chunks"], tenant_ids, chat_mdl, dialog.top_n)
                     if cks:
                         kbinfos["chunks"] = cks
                 kbinfos["chunks"] = retriever.retrieval_by_children(kbinfos["chunks"], tenant_ids)
diff --git a/rag/nlp/search.py b/rag/nlp/search.py
index 01f55c9ef..b10dc8572 100644
--- a/rag/nlp/search.py
+++ b/rag/nlp/search.py
@@ -13,7 +13,6 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 #
-import asyncio
 import json
 import logging
 import re
@@ -589,7 +588,7 @@ class Dealer:
                          key=lambda x: x[1] * -1)[:topn_tags]
         return {a.replace(".", "_"): max(1, c) for a, c in tag_fea}
 
-    def retrieval_by_toc(self, query: str, chunks: list[dict], tenant_ids: list[str], chat_mdl, topn: int = 6):
+    async def retrieval_by_toc(self, query: str, chunks: list[dict], tenant_ids: list[str], chat_mdl, topn: int = 6):
         if not chunks:
             return []
         idx_nms = [index_name(tid) for tid in tenant_ids]
@@ -614,7 +613,7 @@ class Dealer:
         if not toc:
             return chunks
 
-        ids = asyncio.run(relevant_chunks_with_toc(query, toc, chat_mdl, topn * 2))
+        ids = await relevant_chunks_with_toc(query, toc, chat_mdl, topn * 2)
         if not ids:
             return chunks