The invention belongs to the technical field of hydropower engineering maintenance, and especially relates to a management and control system for a maintenance work order of a giant hydropower plant.The management and control system comprises a single chip microcomputer, a water level signal acquisition and conversion module, a water head signal transmission module and a water head signal calculation module; the single chip microcomputer is in signal connection with the water level signal acquisition and conversion module; the single chip microcomputer is in signal connection with the water head signal transmission module; and the single chip microcomputer is in signal connection with the water head signal calculation module. A governor head is changed from manual setting to automatic issuing and self-adaption, three judgment of water head acquisition, water head control and fault tolerance is realized, the system regulation precision and reliability are ensured, and automatic detection, automatic error correction and automatic switching functions of the governor head are realized.