other pepole can unlock my iphone 7 using touch id when i didnt register their finger

FerrariEnzo7979 wrote:

I tried and it dosent work

See this link for guidance --> Set up Touch ID on iPhone - Apple Support

… and never ever disclose your passcode.

When entering it with other individuals nearby, guard it.

You might also consider adding a longer (longer than 6x digits) “custom” numeric passcode.

EASY for you to enter; VERY hard for an observer to remember.

I'd remove your fingerprint and redo it. Then don't let anyone else use your phone.

Settings > Touch ID and Passcode

And you followed Lobsterghost’s recommendation to RESET your TouchID …

… which would have required you to re-register your own fingerprints … ???

Interesting … 🤔