相关文献：http://www.mobilexweb.com/blog/safari-ios7-html5-problems-apis-review
If you are using Application Cache and also managing states through hash or other technique, the history object will not keep your navigation history, therefore history.back() will never work and history.length stays in 1 forever. (Thanks to 10+ people who reported this problem!)
我们这有个项目用了ApplicationCache、在Android和iOS7以下版本都能正常history.back()在不同hash值中跳转。但是在iOS7里面，后退按钮失效了。
整个项目用了ApplicationCache做离线缓存，暂时有个方案就是把ApplicationCache全部改为用localstorage来存储。不过这个工作量略大，求其他方案。
可以参考这篇文章：
http://www.dozer.cc/2014/06/application-cache-bug-in-ios7/
工作量很小