npm install axios --save-dev

import axios from 'axios';

axios.post('http://localhost:3000/users/zhuce',$(form).serialize())

    .then(function(res){

        console.log(res);

        alert(res.data);

    })

    .catch(function(err){

        console.log(err);

    })

npm install  jquery --save-dev 

plugins: [

    new webpack.ProvidePlugin({

         $:"jquery",

         jQuery:"jquery",

         "window.jQuery":"jquery"

      })

    ] 

npm install vue-resource --save-dev 

Vue.use(require('vue-resource'));  //--------添加

callKa:function(event){

      this.$http.get('http://localhost:3000/',{}).then(function(data){

        alert(data.body);

      }).catch(function(err){

          alert('出错');

          for(let key in err){

            console.log(key+':'+err[key]);

          }

      })

    }