function copyUrl() {

        var Url2=document.getElementById("url").innerText;

        var oInput = document.createElement('input');

        oInput.value = Url2;

        document.body.appendChild(oInput);

        oInput.select(); // 选择对象

        document.execCommand("Copy"); // 执行浏览器复制命令

        oInput.style.display='none';

        alert('复制成功');

 }

 <div onclick="copyUrl()">

      <span class="fl">推广链接</span>

      <span  style="display: none;" id="url">http://......</span >

 </div>

 <!-- 1. Define some markup -->

    <input id="foo" type="text" value="hello">

    <button class="btn" data-clipboard-action="copy" data-clipboard-target="#foo">Copy</button>

    <!-- 2. Include library -->

    <script src="../dist/clipboard.min.js"></script>

    <!-- 3. Instantiate clipboard -->

    <script>

    var clipboard = new ClipboardJS('.btn');

    clipboard.on('success', function(e) {

        console.log(e);

    });

    clipboard.on('error', function(e) {

        console.log(e);

    });

    </script>