没找到很好的方法
只好用DOM方法与jquery方法结合的方式实现了

1.在父窗口中操作 选中IFRAME中的所有单选钮
$(window.frames["iframe1"].document).find("input[@type='radio']").attr("checked","true");

2.在IFRAME中操作 选中父窗口中的所有单选钮
$(window.parent.document).find("input[@type='radio']").attr("checked","true");

iframe框架的：

IE7中测试通过 回去你自己试试吧
刚才google到的，补充一下

I beat my head against this wall for quite some time.

Try this:
$("#myid", top.document);
the top.document tells the selector to target the myid element which
exists in the topmost document (your parent page).  In order for this
to work, jquery must be loaded in the file which is viewed through the
iframe.

我的代码
$('#parentElem', top.document).append('');