The present invention relates to a high-pressure pump, and belongs to the manufacturing field of high-pressure pumps. A high-pressure pump includes a pump cover, an air cylinder, a piston, a water cooling device, and a pump seat. The air cylinder is formed by a first air cylinder, a second air cylinder and a third air cylinder whose diameters are progressively reduced and that are coaxially disposed. The piston is also formed by a first piston, a second piston and a third piston whose diameters are progressively reduced and that are respectively disposed in the first air cylinder, the second air cylinder and the third air cylinder. A water cooling device is disposed between the second air cylinder and the third air cylinder. The high-pressure pump further includes: a water cooling detection system, an automatic lubrication system, and an automatic drainage system, so that: I) output working pressure is high; II) a heat dissipation structure is designed, the heat dissipation effect is good, and the high-pressu
