The invention relates to a hydropower station on-off equipment operation and maintenance and fault monitoring online evaluation system and method. The hydropower station on-off equipment operation andmaintenance and fault monitoring online evaluation system comprises a system server, wherein an integrated information database is arranged in the system server, and the hydropower station on-off equipment operation and maintenance and fault monitoring online evaluation system further comprises an intelligent operation and maintenance system, a fault monitoring and early warning system and an online evaluation system which operate in the system server. The intelligent operation and maintenance system comprises an information acquisition module used for acquiring the working state of the on-off equipment, and an operation and maintenance data database connected with the information acquisition module. The fault monitoring and early warning system comprises an information acquisition modulefor acquiring fault information and a fault alarm database connected with the information acquisition module, and the online evaluation system comprises an equipment evaluation database. According tothe hydropower station on-off equipment operation and maintenance and fault monitoring online evaluation system, related personnel can comprehensively understand and grasp the operation state of thestarting and stopping equipment and timely eliminate and repair possible faults, so that the service life of the equipment can be prolonged, and the safe operation of the equipment is guaranteed.