<div class="head">
    <div class="menu fl">
        <ul>
            <li {if condition="empty($__CHANNEL__) && $Think.request.q eq ''" }class="active" {/if}><a
                    href="/">首&nbsp;&nbsp;页</a></li>
            {cms:channellist id="nav" type="top" condition="`isnav`=1" orderby="weigh asc"}
            {cms:query sql="select count(id) as count from jh_cms_channel where parent_id=? and isnav=?"
            id="son_count" bind=":$nav['id'].',1'"}
            <li class="{php}if(in_array($nav['id'],[1,9,24])){echo 'menu_down_more ';}if(!empty($__CHANNEL__) && 
            (($__CHANNEL__['id'] == $nav['id']) || ($__CHANNEL__['parent_id'] == $nav['id']))){echo 'active';} 
            if($nav['id']==9){echo ' head_product_category ';}{/php}">
                <a href="{$nav.url}">{$nav.name}</a>
                {if condition="$son_count.count gt 0"}
                <div class="menu_down">
                    <div class="menu_son">
                        {cms:channellist id="nav_son" typeid="$nav.id" type="son" orderby="weigh asc"}
                        <div class="menu_son_item fl">
                            <a href="{if $nav_son.parent_id==1}/p/qiyejianjie.html#{$nav_son.diyname}{else /}{$nav_son.url}{/if}"
                                rel="noopenner noreferrer">{$nav_son.name}</a>
                        </div>
                        {/cms:channellist}
                    </div>
                </div>
                {/if}
            </li>
            {/cms:query}
            {/cms:channellist}
        </ul>
    </div>
</div>

$(".head .menu li")
.on("mouseenter", function () {
  var $this = $(this);
  $this.find(".menu_down").stop().slideDown().addClass("show");
})
.on("mouseleave", function () {
  var $this = $(this);
  $this.find(".menu_down").stop().slideUp().removeClass("show");
});