Hello 金波 孟,
Thank you for posting in the Q&A forum.
According to my research, Windows 10 by default does not support setting lock screen wallpaper for multiple screens. Normally the lock screen wallpaper will only be displayed on the Primary Screen, while the other screens will show a black screen while screens are locked. This is designed to allow users to quickly and accurately recognize the primary screen and log in every time.
If you want to realize multi-screen lock screen operation, you can also try other third-party products, such as DisplayFushion and so on. I found a document you can refer to: https://zhuanlan.zhihu.com/p/665603299
Thank you very much for your understanding and support.
Best Regards,
Ian Xue
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