diff --git a/backend/modules/llm/domain/service/llmimpl/eino/init.go b/backend/modules/llm/domain/service/llmimpl/eino/init.go
index d81266823..2688bf13f 100644
--- a/backend/modules/llm/domain/service/llmimpl/eino/init.go
+++ b/backend/modules/llm/domain/service/llmimpl/eino/init.go
@@ -135,9 +135,11 @@ func openAIBuilder(ctx context.Context, model *entity.Model, opts ...entity.Opti
 			if err := sonic.UnmarshalString(pc.ResponseFormatJsonSchema, &js); err != nil {
 				return nil, err
 			}
-			cfg.ResponseFormat = &acl_openai.ChatCompletionResponseFormat{
-				Type:       acl_openai.ChatCompletionResponseFormatType(pc.ResponseFormatType),
-				JSONSchema: &js,
+			if pc.ResponseFormatType != "" {
+				cfg.ResponseFormat = &acl_openai.ChatCompletionResponseFormat{
+					Type:       acl_openai.ChatCompletionResponseFormatType(pc.ResponseFormatType),
+					JSONSchema: &js,
+				}
 			}
 		}
 	}