min.js

Vue.http.interceptors.push(function(request, next) {
  let timeout;

  if (request._timeout) {
    timeout = setTimeout ( () => {
      if (request.onTimeout) {
        request.onTimeout (request);
        request.abort()
      }
    }, request._timeout);
  }
  next(function(response) {
    clearTimeout(timeout);
    return response
  })
})

page.vue

this.$http.post(url, {
              _timeout: 2000, // 设置超时两秒
              onTimeout: function (res) {
                 alert('请求失败')
              }
})
.then( (res)  => {
  // ..
}, (res) => {
   // 失败回调
})