Hello doraemon1116,
Thank you for reaching out in Apple Support Communities. We understand you're unable to open an application in macOS Big Sur. We'll be happy to help.
We recommend to restart your Mac in safe mode. This helps to perform a basic check of your startup disk, deletes some system caches and more. Here's an article with more information and the proper steps to take: How to use safe mode on your Mac Once you're in safe mode, please restart your Mac as normal and see if you can open the application without any issues.
In addition, you'll want to verify and see if you have, "Read and Write" set for your permissions: Change permissions for files, folders, or disks on Mac
Best regards.