<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script src="addr/js/jquery.min.js"></script>
</head>
<body>
<button id="loginbtn">按钮</button>
<script>
$(document).on('click','.add',function(){
$('body').append(` <button class="add">add</button>`)
</script>
</body>
</html>
