A control method of a combination lock includes executing a lock management program to obtain the management authority of the combination lock. When any unlocking password of the combination lock is assigned to a third person, the lock management program can tie each authorized unlocking password with its associated information to create a password list. When the unlocking authority of the combination lock is to be changed, the lock management program can display each authorized unlocking password together with its associated information, permitting deletion or change of the selected unlocking password and/or its associated information.