The solenoid valve has a closed cavity with through holes at different positions. Each hole leads to the oil pipe of different solenoid valves. There is a valve in the middle of the cavity and two electromagnets on both sides. When the magnet coil is energized, the valve body will be attracted to which side. Different oil drainage holes will be blocked or leaked by controlling the movement of the valve body. The oil inlet hole is normally open. The hydraulic oil will enter different oil drainage pipes, and then the piston of the oil cylinder will be pushed by the oil pressure. The piston will drive the piston rod, and the piston rod will drive the mechanical device. In this way, the mechanical movement is controlled by controlling the current on/off of the electromagnet.