The invention relates to the field of valves, and specially discloses a cutting device used for a valve rod part. The cutting device comprises a pressing mechanism, a first material receiving device and a power mechanism capable of driving the first material receiving plate to vertically move and horizontally move, which are arranged from top to bottom, wherein the pressing mechanism comprises a pressure plate capable of vertically moving up and down and a discharge plate horizontally arranged, which are sequentially arranged from top to bottom, wherein a vertical through slot for allowing thefirst material receiving plate to pass through is formed in the discharge plate; a plurality of limiting slots which are long as a standard valve rod part are arranged on the upper surface of the discharge plate in a penetrating mode; the limiting slots communicate with a vertical straight slot; the side surfaces of two ports, close to the limiting slots, of the discharge plate are perpendicularto axes of the limiting slots; a baffle plate is fixedly mounted at one side of the discharge plate; the port of the limiting slot close to one side of the pressure plate is aligned to the charge tube; and one end, away from the charge tube, of the limiting slot abuts against the baffle plate. According to the scheme adopted by the invention, the cutting device can perform batch cutting and processing on valve rod parts which are different in length.