object.style.animationDirection="reverse" - 尝试一下 - - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    div {
      width: 100px;
      height: 100px;
      background: red;
      position: relative;
      animation: mymove 5s infinite;

      /* Safari、Chrome 和 Opera */
      -webkit-animation: mymove 5s infinite;
    }

    @keyframes mymove {
      from {
        left: 0px;
      }
      to {
        left: 200px;
      }
    }
    /* Safari、Chrome 和 Opera */

    @-webkit-keyframes mymove {
      from {
        left: 0px;
      }
      to {
        left: 200px;
      }
    }
  </style>

</head>
<body>

  <p>点击“尝试一下”按钮，反转动画的方向。</p>

  <button onclick="myFunction()">尝试一下</button>

  <script>
    function myFunction() {
      document.getElementById("myDIV").style.animationDirection = "reverse";
      // 针对 Chrome、Safari 和 Opera 的代码
      document.getElementById("myDIV").style.WebkitAnimationDirection = "reverse";
    }
  </script>

  <p><strong>注意：</strong>只有 Firefox 支持 animationDirection 属性。</p>

  <div id="myDIV"></div>

</body>
</html>
        