A grinding device for a million nuclear power high pressure valve disc and a valve seat relates to a grinding device for the valve disc and the valve seat. A control bar includes a rotating moment armand a grinding bar; one end of the grinding bar is connected with the center of the rotating moment arm and is arranged to be perpendicular to the rotating moment arm; the other end of the grinding bar is equipped with a groove; one end of a connection stud is equipped with a protuberant platform, the protuberant platform and the groove formed in the other end of the grinding bar are used in cooperation, a part of the inner side surface of a cooperation cone ring is equipped with screw threads, the screw threads of the partial inner side surface of the cooperation cone ring and the screw threads of the circular cylinder surface of the connection stud are used in cooperation, the connection stud can be screwed into the partial space of the cooperation cone ring, the area without screw threads on the inner side surface of the cooperation cone ring is uniformly equipped with a plurality of bolt holes, the bolt holes penetrate the cone ring wall of the cooperation cone ring, and a plurality of bolts are installed in the bolt holes in the direction from the inner side surface of the cooperation cone ring to the outside surface of the cooperation cone ring and the bolts extend out of the bolt holes. The device is used for grinding the million nuclear power high pressure valve disc and the valve seat.