(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.jspid=%=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