<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<button class="btn btn-primary" type="button">点击我</button>
<div class="modal fade" id="mymodal">
<div class="modal-dialog">
<div class="modal-content">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal"><span aria-hidden="true">×</span><span class="sr-only">Close</span></button>
<h4 class="modal-title">模态弹出窗标题</h4>
</div>
<div class="modal-body">
<p>模态弹出窗主体内容</p>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">关闭</button>
<button type="button" class="btn btn-primary">保存</button>
</div>
</div><!-- /.modal-content -->
</div><!-- /.modal-dialog -->
</div><!-- /.modal -->
<script src="https://www.imooc.com/static/lib/jquery/1.9.1/jquery.js"></script>
<script src="http://cdn.bootcss.com/bootstrap/2.3.1/js/bootstrap-transition.js"></script>
<script src="http://cdn.bootcss.com/bootstrap/2.3.1/js/bootstrap-modal.js"></script>
<script>
$(function(){
$(".btn").click(function(){
$("#mymodal").modal("toggle");
});
});
</script>
</body>
</html>
把最下面两个js插件链接换成https就可以了
<script src="https://cdn.bootcss.com/bootstrap/2.3.1/js/bootstrap-transition.js"></script>
<script src="https://cdn.bootcss.com/bootstrap/2.3.1/js/bootstrap-modal.js"></script>