The invention provides a digital lock which comprises a lock core, a spring and tumblers. The digital lock also comprises steel balls, tumbler trigger circuit switches and an alarm circuit. The tumblers comprise upper tumblers and lower tumblers, and the steel balls are arranged between each upper tumbler and each lower tumbler. Each upper tumbler is connected with the spring. When the spring is bounced up, the tumblers connected with the spring trigger on the circuit switches to turn on. When at least one of the tumbler trigger circuit switches is not turned on, the alarm circuit connected with the tumbler trigger circuit switches is used for giving an alarm through dialing a preset alarm number. The digital lock can give an alarm through dialing the telephone number of the owner via a telephone connected with the alarm circuit so as to inform the owner of an illegal entry when an illegal key is inserted into the lock or the lock is pried or destroyed.