diff --git a/subpackages/mine/cancel-registration/cancel-registration.js b/subpackages/mine/cancel-registration/cancel-registration.js
index 699f2b8..2314b49 100644
--- a/subpackages/mine/cancel-registration/cancel-registration.js
+++ b/subpackages/mine/cancel-registration/cancel-registration.js
@@ -146,10 +146,33 @@ Page({
       confirmText: '确定',
       success: (res) => {
         if (!res || !res.confirm) return;
-        // TODO: 接入后端“取消报名/退款”接口后提交所选项目
-        wx.showToast({ title: '已提交（待接接口）', icon: 'none' });
+        this.submitCancelRegistration();
       }
     });
+  },
+
+  submitCancelRegistration() {
+    wx.showLoading({ title: '提交中...' });
+    request({
+      path: API.cancelRegistrationRefund,
+      method: 'POST',
+      needAuth: true,
+      data: {
+        registrationId: this.data.registrationId,
+        refundReason: '用户取消报名'
+      }
+    })
+      .then(() => {
+        wx.hideLoading();
+        wx.showToast({ title: '退款申请已提交', icon: 'success' });
+        setTimeout(() => {
+          wx.navigateBack();
+        }, 1500);
+      })
+      .catch((err) => {
+        wx.hideLoading();
+        wx.showToast({ title: (err && err.message) || '提交失败，请稍后重试', icon: 'none' });
+      });
   }
 });
 
diff --git a/utils/constants.js b/utils/constants.js
index f1909cc..cc59f05 100644
--- a/utils/constants.js
+++ b/utils/constants.js
@@ -12,6 +12,7 @@ const API = {
   myRegistrationDetail: (registrationId) => `/api/eventclient/my-registration/${registrationId}`,
   apply: '/api/eventclient/apply',
   calculateAmount: '/api/eventclient/calculate-amount',
+  cancelRegistrationRefund: '/api/eventclient/cancel-registration-refund',
 
   wechatLogin: '/api/oauth/login',
   loginByCode: '/api/oauth/login',