Hydraulic press is the use of Pascal's principle: closed system working pressure is a time constant. Part of the hydraulic press is a piston, which acts like a pump. 5 tons of high speed punch has a smaller cross-sectional area, resulting in a smaller force, the other part is a large area of the piston, the two working pressure is the same, a large area of the piston its reaction force is also very large. If the pump and the hydraulic cylinder of the stamping die are separated, only a small diameter pipe must be connected to the pump and the hydraulic cylinder, which is very easy to resist the liquid pressure. When the piston moves, the fluid in the hydraulic cylinder (such as hydraulic press fluid) will also be accompanied by the movement. Suppose the liquid can't shrink. The oil volume of small piston displacement hazard is equivalent to that of large piston displacement hazard. So the displacement distance between the two will be different, inversely proportional to the piston area. Therefore, in order to move the larger piston better, the smaller piston must travel a longer distance. Korean high speed punch large piston load rate is large, but the displacement is short, small piston bearing force is small, but the displacement is long, so it conforms to the law of conservation of kinetic energy. If the area of the large piston is increased, the distance of the subject will be shorter. The definition of a hydraulic press can also be used in a hydraulic press forming process.