Reciprocating-type supercharger capable of preventing inner leakage of pressure cylinder

The invention discloses a reciprocating-type supercharger capable of preventing inner leakage of a pressure cylinder. The reciprocating-type supercharger comprises the reciprocating pressure cylinderand a matched pilot operated directional control valve; the pressure cylinder comprises a cylinder body, a piston arranged in the cylinder body, a left piston rod and a right piston rod, wherein the left piston rod and the right piston rod are arranged at the two ends of the piston; the cylinder body comprises a piston cylinder in the middle, a left pressure cylinder body and a right pressure cylinder body, wherein the left pressure cylinder body and the right pressure cylinder body are arranged at the two ends; an A port and a B port of the pilot operated directional control valve are connected with a left piston cavity and a right piston cavity of the pressure cylinder correspondingly; the left piston rod and the right piston rod are provided with oil leaking grooves; a left pressure relief cavity and a right pr