The invention relates to a hydraulic trash remover for a bottom grid diversion dam of a power station, comprising a movable grid bar support frame, a guide wheel positioning device, a hydraulic jack, a lateral pulley positioning device, a corridor, a hydraulic jack supporting seat and fixed grid bars, wherein the hydraulic jack and a lateral positioning pulley are installed on both sides of the corridor, and the hydraulic jack is positioned on the hydraulic jack supporting seat fixed on concrete of a dam body; and the fixed grid bars are installed on the same plane of the movable grid bar support frame on the top of the dam body and are fixed on walls on both sides of the dam body, gaps between movable grid bars and the fixed grid bars installed are well adjusted, the guide wheel positioning device is installed on the lateral face of the movable grid bar support frame so as to ensure that the movable grid bar support frame can be leftwards and rightwards positioned, and a hydraulic system in a control room on the dam top is connected with hydraulic pipelines embedded in grooves on both sides of the dam body. As the structure is adopted, by controlling the hydraulic jack, the movable grid bar support frame is operated to move up and down to make reciprocating movement so that silt can be loosened, and the impulsive force of water is utilized for automatically carrying away the silt, thereby achieving the purposes of automatic trash removal and time and labor saving.