const axios = require('axios');
var fs = require('fs');
 axios.get('http://zhangqiang.win/img/random/2.png', {
  responseType: 'arraybuffer'
 })
  .then(function(response) {
      console.log(response.status);
      console.log(response.headers);
  	fs.writeFile('out.png', response.data, function (err) {
    	if (err) throw err;
    	console.log('保存成功');
 	});
 });```