diff --git a/index.js b/index.js
index cf26378..879140b 100644
--- a/index.js
+++ b/index.js
@@ -154,8 +154,11 @@ class Five {
 
   // 启动http服务
   listen(port = 3000, callback = noop) {
-    this.set({ port })
+    if (this.#online) {
+      return console.error('Server already started')
+    }
 
+    this.set({ port })
     this.#online = true
 
     this.#server = http.createServer()