diff --git a/packages/dbgpt-app/src/dbgpt_app/knowledge/service.py b/packages/dbgpt-app/src/dbgpt_app/knowledge/service.py
index 6e8068daf..798facff9 100644
--- a/packages/dbgpt-app/src/dbgpt_app/knowledge/service.py
+++ b/packages/dbgpt-app/src/dbgpt_app/knowledge/service.py
@@ -99,7 +99,7 @@ class KnowledgeService:
         if request.vector_type == "VectorStore":
             request.vector_type = self.rag_config.storage.vector.get_type_value()
         if request.vector_type == "KnowledgeGraph":
-            knowledge_space_name_pattern = r"^[a-zA-Z0-9\u4e00-\u9fa5]+$"
+            knowledge_space_name_pattern = r"^[_a-zA-Z0-9\u4e00-\u9fa5]+$"
             if not re.match(knowledge_space_name_pattern, request.name):
                 raise Exception(f"space name:{request.name} invalid")
         spaces = knowledge_space_dao.get_knowledge_space(query)
diff --git a/packages/dbgpt-core/src/dbgpt/rag/transformer/llm_extractor.py b/packages/dbgpt-core/src/dbgpt/rag/transformer/llm_extractor.py
index 624b11809..534dc19fe 100644
--- a/packages/dbgpt-core/src/dbgpt/rag/transformer/llm_extractor.py
+++ b/packages/dbgpt-core/src/dbgpt/rag/transformer/llm_extractor.py
@@ -84,7 +84,10 @@ class LLMExtractor(ExtractorBase, ABC):
             logger.error(f"request llm failed ({code}) {reason}")
             return []
 
-        return self._parse_response(response.text, limit)
+        if response.has_text:
+            return self._parse_response(response.text, limit)
+        else:
+            return []
 
     def truncate(self):
         """Do nothing by default."""