Cylinder head valve is the gas distribution component of engine, which is one of the important guarantees of engine power source, and its accuracy will directly determine the overall engine performance. Aiming at cylinder head valve finishing accuracy requirements of a generic generator set engine, by analyzing its technical difficulties, the pros and cons of machining center and special machine tool were compared and special machine tool was selected and designed as valve finishing equipment.Boring and reaming processes were used for machining conduit hole and seat ring hole. Tool materials and various cutting parameters were identified, and then locating and clamping schemes were formulated. The designed process and the special machine tool were successfully implemented in an enterprise in Chongqing. The precision of the workpiece is met or exceeded enterprise requirements, and the takt is of 063 min/pc. 