Four-column hydraulic machine for plastic material pressing process, such as punching, bending, flanging, sheet metal stretching. Also it is engaged in the correction, press-fit, wheel forming, cold extrusion molding metal parts, plastic products and powder products molding process. ? This machine has independent power sector and electrical systems, and the use of centralized control button, can achieve adjustment, manual and semi-automatic operation. ? Working pressure of the machine, pressing speed, travel range may be adjusted according to the process needs. And to complete the process of constant pressure and constant manner forming two processes, constant pressure molding process of the way after pressing with a packing and delay automatic return action.