Building block molding machine is the essential equipment by which the wall brick suppresses shape. With the successful development of domestic automatic hydraulic machines, and users requirements to improve product quality and production efficiency, block molding machine control systems are constantly updated. In order to overcome the limitations of traditional contactors and relays,such as control wiring complexity, job insecurity, low reliability, intelligent control system based on PLC was used to improve the machine hydraulic system.The research provides a theoretical basis for further optimization of building block molding machine hydraulic system.