The invention belongs to the technical field of diaphragm pumps and particularly relates to a high-pressure diaphragm pump piston rod and a washing system using the piston rod. According to the high-pressure diaphragm pump piston rod and the washing system using the piston rod, heat exchange can be conducted on a piston and an oil cylinder, and a cooling effect can be achieved. The high-pressure diaphragm pump piston rod comprises a rod body, and is characterized in that one end of the rod body is connected with an intermediate rod, an oil injection hole is formed in the side face of the end, connected with the intermediate rod, of the rod body, an axial oil way communicated with the oil injection hole is formed in the center of the rod body, and at least three oil spraying holes are circumferentially formed in the side surface of the other end of the rod body; the oil spraying holes are communicated with the axial oil way.