diff --git a/apps/application/flow/step_node/search_document_node/impl/base_search_document_node.py b/apps/application/flow/step_node/search_document_node/impl/base_search_document_node.py
index 53cffc91838..baadd10ac40 100644
--- a/apps/application/flow/step_node/search_document_node/impl/base_search_document_node.py
+++ b/apps/application/flow/step_node/search_document_node/impl/base_search_document_node.py
@@ -59,7 +59,7 @@ def execute(self, knowledge_id_list: List, search_mode: str, search_scope_type:
             )
             authorized_knowledge_ids = get_knowledge_list_of_authorized(
                 self.workflow_manage.get_body().get('chat_user_id'),
-                actual_knowledge_ids
+                [str(k_id) for k_id in actual_knowledge_ids]
             )
             document_id_list = QuerySet(Document).filter(
                 id__in=document_id_list,