The pressurized cylinder is a hydraulic element that can change the input pressure to output at a higher pressure. Booster cylinder is a hydraulic cylinder and the supercharger for one-piece combination, use different compression ratio of the cross section area of the size of the supercharger, because pressure is constant, when the pressure change from big to small, the pressure will change with different sizes and principle, so as to achieve to increase the air pressure to dozens of times the pressure effect, preloading type pressurized cylinder, for example:When work pressure in the hydraulic oil (or piston) surface, the hydraulic oil will be compressed air cavity and flow to the preloading trip, the hydraulic oil will quickly push for displacement, displacement resistance is greater than atmospheric pressure when the work pressure cylinder is to stop the action, at this point, the booster cylinder pressure cavity because electrical signals (or pneumatic) action, start charging so as to achieve the aim of molding products.