<div class="layui-input-inline">
         <button type="button" οnclick="selectRole()" class="layui-btn layui-btn-primary layui-btn-radius">选择角色</button>
         </div>

type="button"属性否则将会有问题

//选择角色弹层
 function selectRole(){
 layer.open({
     //layer提供了5种层类型。可传入的值有：0（信息框，默认）1（页面层）2（iframe层）3（加载层）4（tips层）
      type:1,
      title:"查找用户角色",
      area: ['50%','50%'],
      content:$("#popSearchRoleTest").html()
    });
 }

<!-- 选择角色的按钮 -->
 <div class="layui-row" id="popSearchRoleTest" style="display:none;">
   <div class="layui-col-md11">
     <form class="layui-form" lay-filter="formTestFilter2121" >
       <div class="layui-form-item">
         <label class="layui-form-label">用户名：</label>
         <div class="layui-input-inline">
           <input type="text" name="userName" class="layui-input">
         </div>
         <label class="layui-form-label">密码：</label>
         <div class="layui-input-inline">
         <input type="text" name="password" class="layui-input">
         </div>
       </div>
       <div class="layui-form-item">
         <label class="layui-form-label">角色：</label>
         <div class="layui-input-inline">
           <input type="text" name="roleName" class="layui-input">
         </div>
         <div class="layui-input-inline">
         <button οnclick="selectRole()" class="layui-btn layui-btn-primary layui-btn-radius">选择角色</button>
         </div>
       </div>
       <div class="layui-form-item">
         <label class="layui-form-label">备注：</label>
         <div class="layui-input-block">
           <textarea placeholder="请输入内容" class="layui-textarea" name="userDescription"></textarea>
         </div>
       </div>
       <div class="layui-form-item">
         <div class="layui-input-block">
           <button type="button" class="layui-btn layui-btn-normal">提交</button>
         </div>
       </div>
     </form>
   </div>
 </div>