var b = window.open("", "_blank");
// window.document.head.innerHTML = '<link rel="stylesheet" href="引入文件" />';
b.window.document.body.innerHTML =
'<h1 class="text - center">Hello World</h1>< h1 class="text-center" > Hello World</h1 ><h1 class="text-center">Hello World</h1><h1 class="text-center">Hello World</h1>';
setTimeout(function () {
b.window.print();
}, 50);