Aimed at the processing of the shock absorbers hole that has the characteristics of high requirement like high production rhythm, dimensional tolerance and positional accuracy and so on, a gas liquid combination punching mechanism with two different guide structures is designed. Numerical simulation of the whole punching process was proced with ANSYS/LS-DYNA, by which the relationship curve of the maximal displacement of workpieces bump with the blanking force and the feed speed of punch was obtained. Under the premise of high efficiency and energy saving, the feed speed of punch, exact blanking force and other main technical parameters are confirmed reasonably.