not good.

其实可以用，但是会提示没有安装，但明明可以同步火狐

Crap shoot! Good when it works...Bookmark sync with FF stopped working after iOS 15. Odd behavior on Windows 10 (from the store) client when changing settings attempting to troubleshoot. Change bookmark settings and photo settings get changed. Sadly, no support available as Apple is well known for their lack of support to Windows versions of their products.

Doesn't work after it had worked for several months

There's a problem with either this extension or iCloud.
In the settings panel for iCloud for Windows there is a section called Bookmarks.
It defaults to Internet Explorer!
There is an option to select Firefox instead but when I do (& click 'Apply') it tells me that the iCloud Bookmarks extension for Firefox is required.
I am already aware of this & have installed this Firefox iCloud Bookmarks extension previously.
Unfortunately, iCloud for Windows fails to recognise this & therefor It's not possible to set it up.

无法跳转到软件，导致无法使用。

This doesn't work! Is it Firefox or is it iCloud? iCloud doen't recognize that the extension is already installed in Firefox. As such you cannot sync Safari bookmarks with Firefox. Apparently this 'bug' has been around for a while but as yet it's not been fixed.

Kompatibel mit bestehendem System