开发环境  config/dev.env.js

'use strict'
const merge = require('webpack-merge')
const prodEnv = require('./dev.env')

module.exports = merge(prodEnv, {
  NODE_ENV: '"development"',
  API_ROOT: '"https://www.dev.com"'  //本地请求前缀
})

线上开发环境  config/prod.env.js

'use strict'
const merge = require('webpack-merge')
const prodEnv = require('./prod.env')

module.exports = merge(prodEnv, {
  NODE_ENV: '"production"',
  API_ROOT: '"https://www.prov.com"'   //线上请求前缀
})

在请求之前，组装URL，axios.js

import Axios from 'axios';
var root = process.env.API_ROOT;
//请求拦截
axios.interceptors.request.use((config) => {
    //请求之前重新拼装url
    config.url = root + config.url;
    return config;
});

页面使用模板：

export default {
    name: 'Order',
    data () {
        return {
            order_list: []
        }
    },
    methods: {
        fetchList: function () {
            this.$axios.post('/api/order_list').then((res) => {
                if(res.result === '0000'){
                    this.order_list = res.data;
                }
            });
        }
    }
}