为了更好地理解Transform-Origin属性，请查看这个演示. - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <style>
    #div1 {
      position: relative;
      height: 200px;
      width: 200px;
      margin: 50px;
      padding: 10px;
      border: 1px solid black;
    }

    #div2 {
      padding: 50px;
      position: absolute;
      border: 1px solid black;
      background-color: red;
      transform: rotate(45deg);
      transform-origin: 20% 40%;
      -ms-transform: rotate(45deg);
      /* IE 9 */
      -ms-transform-origin: 20% 40%;
      /* IE 9 */
      -webkit-transform: rotate(45deg);
      /* Safari and Chrome */
      -webkit-transform-origin: 20% 40%;
      /* Safari and Chrome */
      -moz-transform: rotate(45deg);
      /* Firefox */
      -moz-transform-origin: 20% 40%;
      /* Firefox */
      -o-transform: rotate(45deg);
      /* Opera */
      -o-transform-origin: 20% 40%;
      /* Opera */
    }
  </style>
  <script>
    function changeRot(value) {
      document.getElementById('div2').style.transform = "rotate(" + value + "deg)";
      document.getElementById('div2').style.msTransform = "rotate(" + value + "deg)";
      document.getElementById('div2').style.webkitTransform = "rotate(" + value + "deg)";
      document.getElementById('div2').style.MozTransform = "rotate(" + value + "deg)";
      document.getElementById('div2').style.OTransform = "rotate(" + value + "deg)";
      document.getElementById('persp').innerHTML = value + "deg";
    }

    function changeOrg() {
      var x = document.getElementById('ox').value;
      var y = document.getElementById('oy').value;
      document.getElementById('div2').style.transformOrigin = x + '% ' + y + '%';
      document.getElementById('div2').style.msTransformOrigin = x + '% ' + y + '%';
      document.getElementById('div2').style.webkitTransformOrigin = x + '% ' + y + '%';
      document.getElementById('div2').style.MozTransformOrigin = x + '% ' + y + '%';
      document.getElementById('div2').style.OTransformOrigin = x + '% ' + y + '%';
      document.getElementById('origin').innerHTML = x + "% " + y + "%";
    }
  </script>
</head>

<body>

  <p>Rotate the red div element, try changing its X-axis and Y-axis:</p>

  <div id="div1">
    <div id="div2">HELLO</div>
  </div>

  Rotate:
  <input type="range" min="-360" max="360" value="45" onchange="changeRot(this.value)" /> transform: rotateY:(<span id="persp">45deg</span>);
  <br><br> X-axis:
  <input type="range" min="-100" max="200" value="20" onchange="changeOrg()" id="ox" /><br> Y-axis:
  <input type="range" min="-100" max="200" value="40" onchange="changeOrg()" id="oy" /> transform-origin: <span id="origin">20% 40%</span>;

</body>
</html>
        