今天打开配置文件发现多出这么多文件不知道如何造成的

是什么扩展设置备份了首选项文件么？

fang5566：是什么扩展设置备份了首选项文件么？回到原帖

没有这样的扩展。

Firefox first creates a numbered temp file (prefs-##.js in this case) as a safety precaution and when creating file has finished without errors then the numbered temp file is renamed to the main file without the number (prefs.js). Only when the latter (renaming) fails you will see the numbered file stay and that is what is happening in your case.
I assume that your security software immediately tries to scan the file while Firefox is working with it and that prevents Firefox from renaming the file because other software has a handle on it. It is normally best to exclude the Firefox profile folder in security software from scanning to avoid just these issues.  

检查你杀毒软件的设置，扫描之类的功能排除掉Firefox配置文件夹
Why Firefox keep creating prefs.js files? | Firefox Support Forum | Mozilla Support
https://support.mozilla.org/en-US/questions/1203931

infinity：检查你杀毒软件的设置，扫描之类的功能排除掉Firefox配置文件夹
Why Firefox keep creating prefs.js files? | Firefox Support Forum | Mozilla Support
...回到原帖

我用的win10自带的杀毒软件很久了，一直没发现这个问题。15号还有，当天删除所有到晚上没出现过。我在观察一下。

marb：我用的win10自带的杀毒软件很久了，一直没发现这个问题。15号还有，当天删除所有到晚上没出现过。我在观察一下。回到原帖

今天又出现了。