html

<div class="layui-form-item layui-hide">
        <label class="layui-form-label">动物级别</label>
        <div class="layui-input-inline">
          <select name="zoon_id" lay-filter="demo">
            <option value="" >点击选择</option>
            {volist name= "$zoon" id="vo"}
            <option value="{$vo.id}" {notempty name="$info.zoon_id"}{/notempty}>{$vo.zoonlevel}级</option>
            {/volist}
          </select>
        </div>
      </div>

js

<script src="__PUBLIC__/layui/layui.js"></script>
<script>
    layui.use(['layer', 'jquery', 'form'], function () { 
           var layer = layui.layer,
              $ = layui.jquery;
            form = layui.form;

      form.on('select(demo)', function(data){
        console.log(data.value);
          $.ajax({
              url:"{:url('admin/activity/getprize')}",
              data:{pid:id,level:data.value},
              type:'post',
              async: false,
              success:function(res) {
                  layui.form.render();
              }
          })
      });
    });</script>