diff --git a/src/plugins/built_in/knowledge/lpmm_get_knowledge.py b/src/plugins/built_in/knowledge/lpmm_get_knowledge.py
index 174bef1c..bb627e5e 100644
--- a/src/plugins/built_in/knowledge/lpmm_get_knowledge.py
+++ b/src/plugins/built_in/knowledge/lpmm_get_knowledge.py
@@ -15,7 +15,7 @@ class SearchKnowledgeFromLPMMTool(BaseTool):
     description = "从知识库中搜索相关信息，如果你需要知识，就使用这个工具"
     parameters = [
         ("query", ToolParamType.STRING, "搜索查询关键词", True, None),
-        ("limit", ToolParamType.INTEGER, "希望返回的相关知识条数，默认5", False, 5),
+        ("limit", ToolParamType.INTEGER, "希望返回的相关知识条数，默认5", False, None),
     ]
     available_for_llm = global_config.lpmm_knowledge.enable