就是说，页面整体宽度是超出浏览器宽度的，让这个页面自动从左侧滚到右，再滚回来，这么循环滚动
<!doctype html>
<style>body{margin:0}</style>
<div>111<script>document.write('123456789'.repeat('30'))</script></div>
<script>
var root = document.compatMode == 'CSS1Compat' ? 'documentElement' : 'body'
, clientWidth = document[root].clientWidth, scrollWidth = document[root].scrollWidth
, step = 100, delay = 200;
window.onresize = function () { clientWidth = document[root].clientWidth; scrollWidth = document[root].scrollWidth }
if (scrollWidth > clientWidth) setInterval(function () {
document[root].scrollLeft += step;
if (document[root].scrollLeft >= scrollWidth - clientWidth || document[root].scrollLeft == 0) step = -step;
}, delay)
</script>
最外层加个div，加动画或值js定时
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title> 页面名称 </title>
</head>
<body>
<img src="1.jpg" width="2500" height="800" border="0" alt="">
<script type="text/javascript">
var tfv = 5;
setInterval(function(){
var robj = document.compatMode=="CSS1Compat" ? document.documentElement : document.body;
robj.scrollLeft += tfv;
if (robj.scrollLeft<=0 || robj.scrollLeft>=robj.scrollWidth-robj.clientWidth)
tfv = -tfv;
}, 50);
</script>
</body>
</html>