<!DOCTYPE html><html>
<head>
<meta charset="UTF-8">
<title>按钮倒数5秒后才能点击</title>
</head>
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<body>
<button type="button" id="test" disabled>点击</button>
</body>
<script type="text/javascript">
setTimeout(function(){
$("button[id='test']").removeAttr("disabled");
},5000)
</script>
</html>