diff --git a/api/db/services/llm_service.py b/api/db/services/llm_service.py
index c484afcc3b..5906927b7b 100644
--- a/api/db/services/llm_service.py
+++ b/api/db/services/llm_service.py
@@ -82,9 +82,9 @@ def model_instance(cls, tenant_id, llm_type,
         if model_config: model_config = model_config.to_dict()
         if not model_config:
             if llm_type in [LLMType.EMBEDDING, LLMType.RERANK]:
-                llm = LLMService.query(llm_name=llm_name)
+                llm = LLMService.query(llm_name=llm_name if llm_name else mdlnm)
                 if llm and llm[0].fid in ["Youdao", "FastEmbed", "BAAI"]:
-                    model_config = {"llm_factory": llm[0].fid, "api_key":"", "llm_name": llm_name, "api_base": ""}
+                    model_config = {"llm_factory": llm[0].fid, "api_key":"", "llm_name": llm_name if llm_name else mdlnm, "api_base": ""}
             if not model_config:
                 if llm_name == "flag-embedding":
                     model_config = {"llm_factory": "Tongyi-Qianwen", "api_key": "",