diff --git a/index.js b/index.js
index cb721bf..d2765a9 100644
--- a/index.js
+++ b/index.js
@@ -111,7 +111,8 @@ app.post("/v1/messages", apiKeyAuth, (req, res) => {
 						})
 						.join("\n\n");
 
-					userQuery = "Please view the document and reply.";
+					// 试算最新一条human消息长度
+					if(encodeURIComponent(userQuery).length > 30000) userQuery = "Please view the document and reply.";
 					userMessage = [];
 
 					// GET https://you.com/api/get_nonce to get nonce