diff --git a/pilot/scene/chat_knowledge/default/chat.py b/pilot/scene/chat_knowledge/default/chat.py
index 325b03783..3f21b828d 100644
--- a/pilot/scene/chat_knowledge/default/chat.py
+++ b/pilot/scene/chat_knowledge/default/chat.py
@@ -1,3 +1,5 @@
+from chromadb.errors import NoIndexException
+
 from pilot.scene.base_chat import BaseChat, logger, headers
 from pilot.scene.base import ChatScene
 from pilot.common.sql_database import Database
@@ -46,12 +48,15 @@ class ChatDefaultKnowledge(BaseChat):
         )
 
     def generate_input_values(self):
-        docs = self.knowledge_embedding_client.similar_search(
-            self.current_user_input, CFG.KNOWLEDGE_SEARCH_TOP_SIZE
-        )
-        context = [d.page_content for d in docs]
-        context = context[:2000]
-        input_values = {"context": context, "question": self.current_user_input}
+        try:
+            docs = self.knowledge_embedding_client.similar_search(
+                self.current_user_input, CFG.KNOWLEDGE_SEARCH_TOP_SIZE
+            )
+            context = [d.page_content for d in docs]
+            context = context[:2000]
+            input_values = {"context": context, "question": self.current_user_input}
+        except NoIndexException:
+            raise ValueError("you have no default knowledge store, please execute python knowledge_init.py")
         return input_values
 
     def do_with_prompt_response(self, prompt_response):
diff --git a/tools/knowlege_init.py b/tools/knowlege_init.py
index 26338df1c..c9a0c5457 100644
--- a/tools/knowlege_init.py
+++ b/tools/knowlege_init.py
@@ -43,7 +43,6 @@ if __name__ == "__main__":
     parser.add_argument("--vector_name", type=str, default="default")
     args = parser.parse_args()
     vector_name = args.vector_name
-    append_mode = args.append
     store_type = CFG.VECTOR_STORE_TYPE
     vector_store_config = {"vector_store_name": vector_name}
     print(vector_store_config)