The invention discloses a three-card-in-one based transformer substation tool management system and method. The management system comprises a RFID electronic tag for identifying uniqueness of cards, a portable RFID reader for reading information of three types of RFID electronic tag identification cards of transformer substation workers, temporary ground wires and temporary ground points, a fixed RFID reader for reading electronic tag information in the identification cards of the temporary ground wires; a Zigbee router and coordinator for achieving information transfer of the portable RFID readers and a control center, and the background control center for state display of the temporary ground wires of a transformer substation and alarm information processing and storage. The three-card-in-one based transformer substation tool management system and method can be applied to building of an intelligent power grid, can improve the management level of power enterprises, meanwhile can effectively and completely eradicate missed ground wire taking, missed ground wire dismounting, switching-on with the ground wires and other malignant misoperation accidents, guarantees the power grid, equipment and personal safety to the most extent and has high application value.