Why when I restart my mac from any user account it restarts back to the main user account without login?

hi, have you tried disabling auto login? You do this in sys prefs -> accounts

ok I’ll check. Its my account I’m refering to. I mean at login page I have to login with password and all however when I restart no matter what account it auto log in into by account without password

There’s a setting (under Accounts) that determines which account the Mac logs into when it powers on. You’ve probably got your Mac set up to auto-log in.