<iframe frameborder="0" id="iframe1"></iframe>
$('#iframe1').attr('src', 'www.baidu.com');
document.getElementById("iframe1").contentDocument.location.reload();
自适应高度:
var ifm = document.getElementById(iframe);
ifm.height = 100;
var subWeb = document.frames ? document.frames[iframe].document : ifm.contentDocument;
if (ifm != null && subWeb != null) {
ifm.height = subWeb.body.scrollHeight;
}