diff --git a/api/.env.example b/api/.env.example
index e12c76a229f16a..95c64f48524a5a 100644
--- a/api/.env.example
+++ b/api/.env.example
@@ -412,4 +412,4 @@ RESET_PASSWORD_TOKEN_EXPIRY_MINUTES=5
 
 CREATE_TIDB_SERVICE_JOB_ENABLED=false
 
-RETRIEVAL_TOP_N=
+RETRIEVAL_TOP_N=0
\ No newline at end of file
diff --git a/api/configs/feature/__init__.py b/api/configs/feature/__init__.py
index ce9f8f2725dce9..2fdf151e038e1e 100644
--- a/api/configs/feature/__init__.py
+++ b/api/configs/feature/__init__.py
@@ -621,7 +621,7 @@ class DataSetConfig(BaseSettings):
         default=30,
     )
 
-    RETRIEVAL_TOP_N: Optional[PositiveInt] = Field(description="number of retrieval top_n", default=None)
+    RETRIEVAL_TOP_N: int = Field(description="number of retrieval top_n", default=0)
 
 
 class WorkspaceConfig(BaseSettings):
diff --git a/docker/docker-compose.yaml b/docker/docker-compose.yaml
index a9564976fc67ce..aa3c810d3faff0 100644
--- a/docker/docker-compose.yaml
+++ b/docker/docker-compose.yaml
@@ -287,7 +287,7 @@ x-shared-env: &shared-api-worker-env
   OCEANBASE_CLUSTER_NAME: ${OCEANBASE_CLUSTER_NAME:-difyai}
   OCEANBASE_MEMORY_LIMIT: ${OCEANBASE_MEMORY_LIMIT:-6G}
   CREATE_TIDB_SERVICE_JOB_ENABLED: ${CREATE_TIDB_SERVICE_JOB_ENABLED:-false}
-  RETRIEVAL_TOP_N: ${RETRIEVAL_TOP_N:-}
+  RETRIEVAL_TOP_N: ${RETRIEVAL_TOP_N:-0}
 
 services:
   # API service