The invention elates to the technical field of intelligent locking devices used in transformer stations, power plants, and the like, and provides an electromechanical integrated computer key, an intelligent locking device and a working method thereof. The computer key includes a shell, a power supply, a code reading head, an unlocking head, a control unit and an electrifying conductor used for transmitting the power supply and communication signal. The power supply and the control unit are in the inner cavity of the shell. The code reading head is in the shell and mounted at the top end of the shell. The unlocking head is mounted at the top of the shell. The top end of the unlocking head protrudes out of the shell. The bottom end of the electrifying conductor is electrically connected to the control unit. The computer key and an intelligent lock in the intelligent locking device achieve power supplying and work signal transmission through the electrifying conductor, thus providing reliable guarantees for electronization of the intelligent lock. The computer key can unlock locks having present mechanical configurations, and also can unlock electronic lock cores requiring power supplies, and therefore the adaptive range of an intelligent lock management system is wider.