(人笨，占时想法的办法，不要骂，不要骂，怕了怕了)
父页面;
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title><!-- keep on record 备案 --></title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link rel="stylesheet" href="<%=basePath %>base/layuiadmin/layui/css/layui.css" media="all">
<link rel="stylesheet" href="<%=basePath %>base/layuiadmin/style/admin.css" media="all">
</head>
<body>
<div class="layui-fluid"><!-- 布局容器 -->
<div class="layui-row layui-col-space15"> <!-- 列间距 -->
<div class="layui-col-md12"><!-- 列元素 -->
<div class="layui-card"><!-- 卡片面板 -->
<div class="layui-card-body" style="padding: 15px;">
<form class="layui-form" action="" lay-filter="keep-on-record">
<div class="layui-collapse">
<div class="layui-colla-item">
<h2 class="layui-colla-title">提交资料自检</h2>
<div class="layui-colla-content layui-show">
<iframe name="receiving" lay-filter="receiving" id="receiving" src="projects/Post_certificate/Head.jsp?id=<%=id %>" style="width: 100%; height: 86%;"></iframe>
</div>
</div>
</div>
<div class="layui-form-item layui-layout-admin">
<div class="layui-input-block">
<div class="layui-footer" style="left: 0;">
<button type="button" class="layui-btn" id="save">保存</button>
<button type="reset" class="layui-btn layui-btn-primary" id='close'>关闭</button>
</div>
</div>
</div>
</form>
</div>
</div>
</div>
</div>
</div>
<script src="<%=basePath %>base/layuiadmin/layui/layui.js"></script>
</body>
<script>
// 当你使用表单时，layui 会对 select、checkbox、radio 等原始元素隐藏，从而进行美化修饰处理。但这需要依赖于 form 组件，所以你必须加载 form，并且执行一个实例
layui.use(['form','laydate','element'], function(){
var $ = layui.$;
var form = layui.form //只有执行了这一步，部分表单元素才会自动修饰成功
,element = layui.element
,laydate = layui.laydate
,layer = layui.layer
,layero = layui.layero;
$('#save').click(function(){
console.log("----");
var childWindow = $("#receiving")[0].contentWindow;
childWindow.bridging();
/* 调用 Head.jsp 下的 bridging ()，
此方法是外部方法，还需在 Head.jsp 下编写方法 调用 layui.use() 内的方法 ，
因为 需要获得 Head.jsp 内的表单数据，
也可以在 Head.jsp 外部的方法获得表单 数据*/
});
});
</script>
</html>
子页面：
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title><!-- --></title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<link rel="stylesheet" href="<%=basePath %>base/layuiadmin/layui/css/layui.css" media="all">
<link rel="stylesheet" href="<%=basePath %>base/layuiadmin/style/admin.css" media="all">
</head>
<body>
<form class="layui-form" action="" lay-filter="header-information">
<!-- 吧啦吧啦 的 表单内容 -->
</form>
<script src="<%=basePath %>base/layuiadmin/layui/layui.js"></script>
</body>
<script>
// 当你使用表单时，layui 会对 select、checkbox、radio 等原始元素隐藏，从而进行美化修饰处理。但这需要依赖于 form 组件，所以你必须加载 form，并且执行一个实例
layui.use(['form','element'], function(){
var $ = layui.$;
var form = layui.form //只有执行了这一步，部分表单元素才会自动修饰成功
,element = layui.element;
window.head2 = function () { // 写一个全局方法
console.log("进入内部");
};
function head(){
//获取表单区域所有值
var data = form.val("header-information");
console.log(data);
}
});
function bridging(){
//console.log("--------------");
head2(); // 调用全局方法
}
</script>
</html>