var page = require('webpage').create();

 var address = 'https://www.baidu.com/';//填写需要打印的文件位置

 var output = './img/'+'baidu'+'.png';//存储文件路径和名称

 page.viewportSize = { width: 100, height: 100 };//设置长宽

 page.open(address, function (status) {

     if (status !== 'success') {

         console.log('Unable to load the address!');

         phantom.exit();

     } else {

         window.setTimeout(function () {

             page.render(output);

             phantom.exit();

         }, 500);

     }

 });

phantomjs pageload.js