If you forget your Apple Watch passcode
If your Apple Watch is disabled because you forgot your passcode or entered an incorrect passcode too many times, you can use the Apple Watch app on your iPhone to allow you to enter the passcode again. If you still can’t remember your passcode, you can reset Apple Watch, reset the passcode, then restore Apple Watch from a backup. Restoring erases the content and settings on your Apple Watch, but uses a backup to replace your data and settings.
If you can’t access the Settings app on your Apple Watch because you’ve forgotten your passcode, put your Apple Watch on its charger, then press and hold the side button until you see Power Off. Press and hold the Digital Crown, then tap Reset.
After the reset finishes and your Apple Watch restarts, you need to pair your Apple Watch with your iPhone again—open the Apple Watch app on your iPhone, then follow the instructions shown on your iPhone and Apple Watch.
Important: If Erase Data is turned on, the data on your Apple Watch is erased after 10 failed passcode attempts.