@梦浪的小虾米，一般来说，只要把第二个插件粘贴在第一个插件的尾部，两个插件就可以一起使用了。
比如第一个插件的内容是：

<script src="/tpl/jhin/js/jquery-3.1.1.min.js"></script>
<script>
$(function(){
  var head = "<!-- markdown -->\n";
  $('#reply_topic_button,#quick_chat_button,#post_topic_button').click(function(){
    var content = $('#content').val();
    if (head == content.substr(0, head.length)) head = '';
    $('#content').val(head + content);
  })
});
</script>

第二个插件的内容是：

<script src="/tpl/jhin/js/jquery-3.1.1.min.js"></script>
<script>
$(document).ready(function () {
  $("#content").after('<p id="face"><img title="冷" src="/tpl/classic/img/face/e586b7.gif" /><img title="勉强" src="/tpl/classic/img/face/e58b89e5bcba.gif" /><img title="吐舌" src="/tpl/classic/img/face/e59090e8888c.gif" /><img title="吐" src="/tpl/classic/img/face/e59090.gif" /><img title="呵呵" src="/tpl/classic/img/face/e591b5e591b5.gif" /><img title="呼" src="/tpl/classic/img/face/e591bc.gif" /><img title="咦" src="/tpl/classic/img/face/e592a6.gif" /><img title="哈哈" src="/tpl/classic/img/face/e59388e59388.gif" /><img title="啊" src="/tpl/classic/img/face/e5958a.gif" /><img title="喷" src="/tpl/classic/img/face/e596b7.gif" /><img title="太开心" src="/tpl/classic/img/face/e5a4aae5bc80e5bf83.gif" /><img title="委屈" src="/tpl/classic/img/face/e5a794e5b188.gif" /><img title="开心" src="/tpl/classic/img/face/e5bc80e5bf83.gif" /><img title="怒" src="/tpl/classic/img/face/e68092.gif" /><img title="惊哭" src="/tpl/classic/img/face/e6838ae593ad.gif" /><img title="惊讶" src="/tpl/classic/img/face/e6838ae8aeb6.gif" /><img title="汗" src="/tpl/classic/img/face/e6b197.gif" /><img title="泪" src="/tpl/classic/img/face/e6b3aa.gif" /><img title="滑稽" src="/tpl/classic/img/face/e6bb91e7a8bd.gif" /><img title="狂汗" src="/tpl/classic/img/face/e78b82e6b197.gif" /><img title="疑问" src="/tpl/classic/img/face/e79691e997ae.gif" /><img title="真棒" src="/tpl/classic/img/face/e79c9fe6a392.gif" /><img title="睡觉" src="/tpl/classic/img/face/e79da1e8a789.gif" /><img title="笑眼" src="/tpl/classic/img/face/e7ac91e79cbc.gif" /><img title="花心" src="/tpl/classic/img/face/e88ab1e5bf83.gif" /><img title="鄙视" src="/tpl/classic/img/face/e98499e8a786.gif" /><img title="酷" src="/tpl/classic/img/face/e985b7.gif" /><img title="钱" src="/tpl/classic/img/face/e992b1.gif" /><img title="阴险" src="/tpl/classic/img/face/e998b4e999a9.gif" /><img title="黑线" src="/tpl/classic/img/face/e9bb91e7babf.gif" /></p>');
  $('#face img').click(function () {
    var title = "{" +  $(this).attr("title") + "}";
    var oldvalue =  $("#content").val();
    $("#content").val(oldvalue + title);
  });
});
</script>

那么要一起使用的话，只需要放在一起：

<script src="/tpl/jhin/js/jquery-3.1.1.min.js"></script>
<script>
$(function(){
  var head = "<!-- markdown -->\n";
  $('#reply_topic_button,#quick_chat_button,#post_topic_button').click(function(){
    var content = $('#content').val();
    if (head == content.substr(0, head.length)) head = '';
    $('#content').val(head + content);
  })
});
</script>
<script src="/tpl/jhin/js/jquery-3.1.1.min.js"></script>
<script>
$(document).ready(function () {
  $("#content").after('<p id="face"><img title="冷" src="/tpl/classic/img/face/e586b7.gif" /><img title="勉强" src="/tpl/classic/img/face/e58b89e5bcba.gif" /><img title="吐舌" src="/tpl/classic/img/face/e59090e8888c.gif" /><img title="吐" src="/tpl/classic/img/face/e59090.gif" /><img title="呵呵" src="/tpl/classic/img/face/e591b5e591b5.gif" /><img title="呼" src="/tpl/classic/img/face/e591bc.gif" /><img title="咦" src="/tpl/classic/img/face/e592a6.gif" /><img title="哈哈" src="/tpl/classic/img/face/e59388e59388.gif" /><img title="啊" src="/tpl/classic/img/face/e5958a.gif" /><img title="喷" src="/tpl/classic/img/face/e596b7.gif" /><img title="太开心" src="/tpl/classic/img/face/e5a4aae5bc80e5bf83.gif" /><img title="委屈" src="/tpl/classic/img/face/e5a794e5b188.gif" /><img title="开心" src="/tpl/classic/img/face/e5bc80e5bf83.gif" /><img title="怒" src="/tpl/classic/img/face/e68092.gif" /><img title="惊哭" src="/tpl/classic/img/face/e6838ae593ad.gif" /><img title="惊讶" src="/tpl/classic/img/face/e6838ae8aeb6.gif" /><img title="汗" src="/tpl/classic/img/face/e6b197.gif" /><img title="泪" src="/tpl/classic/img/face/e6b3aa.gif" /><img title="滑稽" src="/tpl/classic/img/face/e6bb91e7a8bd.gif" /><img title="狂汗" src="/tpl/classic/img/face/e78b82e6b197.gif" /><img title="疑问" src="/tpl/classic/img/face/e79691e997ae.gif" /><img title="真棒" src="/tpl/classic/img/face/e79c9fe6a392.gif" /><img title="睡觉" src="/tpl/classic/img/face/e79da1e8a789.gif" /><img title="笑眼" src="/tpl/classic/img/face/e7ac91e79cbc.gif" /><img title="花心" src="/tpl/classic/img/face/e88ab1e5bf83.gif" /><img title="鄙视" src="/tpl/classic/img/face/e98499e8a786.gif" /><img title="酷" src="/tpl/classic/img/face/e985b7.gif" /><img title="钱" src="/tpl/classic/img/face/e992b1.gif" /><img title="阴险" src="/tpl/classic/img/face/e998b4e999a9.gif" /><img title="黑线" src="/tpl/classic/img/face/e9bb91e7babf.gif" /></p>');
  $('#face img').click(function () {
    var title = "{" +  $(this).attr("title") + "}";
    var oldvalue =  $("#content").val();
    $("#content").val(oldvalue + title);
  });
});
</script>

就可以了。一般来说，只要这两个插件不是作用在同一个地方，就不会产生冲突。不用管它们引用了相同的js文件啊之类的事情，并不会发生什么问题。

回帖插件测试楼

你可以在任何地方插入注释
使用html注释标记 <!-- 和 -->

<!--插件1-->
<script>
…………
</script>

<!--插件2-->
<script>
…………
</script>

注释也可以用来屏蔽插件：

<!--插件1关闭
<script>
…………
</script>
-->

<!--插件2启用-->
<script>
…………
</script>

@梦浪的小虾米，我已经开始请求虎友帮我实现这个功能了
https://hu60.net/q.php/bbs.topic.86492.html