The valve plate is one of the important parts of the air compressor, which can not be underestimated. The valve plate includes suction hole, exhaust hole and multiple installation holes, the existing technology of multiple installation holes are a processing molding, so both ends of the hole will have burr, so the installation accuracy will be low; And valve plate with grooves, described vent setting in the slots, since the technology on either side of the vent groove is vertical, so air is exhaust valve block and will impact on either side of the vent groove, because the air directly to vent groove on both sides of the vertical plane, so will affect the airflow flowing, additional vents on both sides of the groove and the distance between the vent is short, So the volume of the exhaust channel is smaller, resulting in greater exhaust resistance. Piston air compressor is used for suction and exhaust valve plates, and its working principle is to rely on the piston and start producing suction and exhaust, the piston is inspiratory, down is up exhaust in is outside of the gas, in the suction piston by the piston to compress and then discharged into air cylinder, so that to return after back and forth with high-speed operation to create pressure.