diff --git a/agent/tools/exesql.py b/agent/tools/exesql.py
index 012b00d84..8f3f9dd17 100644
--- a/agent/tools/exesql.py
+++ b/agent/tools/exesql.py
@@ -86,6 +86,12 @@ class ExeSQL(ToolBase, ABC):
 
         def convert_decimals(obj):
             from decimal import Decimal
+            import math
+            if isinstance(obj, float):
+                # Handle NaN and Infinity which are not valid JSON values
+                if math.isnan(obj) or math.isinf(obj):
+                    return None
+                return obj
             if isinstance(obj, Decimal):
                 return float(obj)  # 或 str(obj)
             elif isinstance(obj, dict):