<script src="/js/jquery-1.11.1.min.js"></script>
var txt2=$("<i></i>").text("love ");
var txt3=document.createElement("big");
txt3.innerHTML="jQuery!";
$("img").after(txt1,txt2,txt3);
<img src="/img/eg_W3xue.gif" alt="W3xue Logo" />
<button onclick="afterText()">在图片后面添加文本</button>