The invention discloses a utility car leasing system and an encryption and decryption device and method thereof. The utility car leasing system comprises a station controller, multiple car lockers, multiple types of car borrowing cards and the encryption and decryption device; the station controller comprises a station MCU and a station communication module under the control of the station MCU; each car locker commons a car locker MCU and a car locker card-reading module and a car locker communication module under the control of the car locker MCU; the encryption and decryption device comprises stacked n layers of PSAM array panels, wherein n is an integer greater than one; the station controller, the multiple car lockers and the encryption and decryption device are in communication through a bus; each layer of PSAM array panel is provided with an MCU and a PSAM array connected with the MCU and composed of multiple PSAM cards. The encryption and decryption device in the utility car leasing system can be subjected to centralized management and control and distribute data of the multiple car borrowing cards read by the car lockers, therefore the problem of communication resource occupation can be solved, and cost is saved.