diff --git a/rag/prompts/generator.py b/rag/prompts/generator.py
index 3037e0c4a3..6896ce7a43 100644
--- a/rag/prompts/generator.py
+++ b/rag/prompts/generator.py
@@ -265,12 +265,15 @@ async def cross_languages(tenant_id, llm_id, query, languages=[]):
     from common.constants import LLMType
     from api.db.services.llm_service import LLMBundle
     from api.db.services.tenant_llm_service import TenantLLMService
-    from api.db.joint_services.tenant_model_service import get_model_config_by_type_and_name
+    from api.db.joint_services.tenant_model_service import get_model_config_by_type_and_name, get_tenant_default_model_by_type
 
     if llm_id and TenantLLMService.llm_id2llm_type(llm_id) == "image2text":
         chat_model_config = get_model_config_by_type_and_name(tenant_id, LLMType.IMAGE2TEXT, llm_id)
     else:
-        chat_model_config = get_model_config_by_type_and_name(tenant_id, LLMType.CHAT, llm_id)
+        if not llm_id:
+            chat_model_config = get_tenant_default_model_by_type(tenant_id, LLMType.CHAT)
+        else:
+            chat_model_config = get_model_config_by_type_and_name(tenant_id, LLMType.CHAT, llm_id)
     chat_mdl = LLMBundle(tenant_id, chat_model_config)
     rendered_sys_prompt = PROMPT_JINJA_ENV.from_string(CROSS_LANGUAGES_SYS_PROMPT_TEMPLATE).render()
     rendered_user_prompt = PROMPT_JINJA_ENV.from_string(CROSS_LANGUAGES_USER_PROMPT_TEMPLATE).render(query=query,