diff --git a/src/mock/index.js b/src/mock/index.js
index f22c762f..c7c8f004 100644
--- a/src/mock/index.js
+++ b/src/mock/index.js
@@ -11,6 +11,8 @@ Mock.XHR.prototype.proxy_send = Mock.XHR.prototype.send
 Mock.XHR.prototype.send = function() {
   if (this.custom.xhr) {
     this.custom.xhr.withCredentials = this.withCredentials || false
+    // 确保 responseType 不会丢失
+    this.custom.xhr['responseType'] = this['responseType']
   }
   this.proxy_send(...arguments)
 }