簡單搞定了
?<div>
? ? <span id="time">5</span>
? ? <span>秒后返回主頁</span>
? ? <a href="" onclick="go()">返回</a>
? ?</div>
<script>
???? function go(){
???????? history.go(-1);
???????? }
????????? ?var num=5;
???? function jishi(){
???????? document.getElementById("time").innerText=num;
???????? if(num==0){
???????? window.open("https://www.baidu.com",'_blank','width:600','height:400');
???????? clearInterval(insd);
???????? }else{
???????? num=num-1;
???????? }
???????? }
???????? var insd=setInterval("jishi()",1000);
</script>
