The ship hatch cover hydraulic power unit (HPU) is used as an oil supply device, which is connected to several hydraulic cylinders through an external pipeline system to control the actions of multiple sets of valves. Oil tank, oil pump and accumulator form an independent closed power oil source system. The oil station can be equipped with a PLC control system, which controls all internal hydraulic functions and generates signals for exchange with the control room (DCS). Control components such as hydraulic servo valves are directly installed on the hydraulic cylinder, and high-pressure oil is pressed into the cylinder through this valve, or high-pressure oil is discharged from it. Under normal conditions, the oil pump supplies oil to the system, automatically maintains the rated pressure of the system, and realizes the function of holding the valve at any position through the blocking of the control valve; in the working state, the hydraulic actuator is controlled by the solenoid valve and the system command signal The solenoid valve is actuated to control the oil pressure and the energy release of the accumulator, and then the oil cylinder slide valve is controlled, and the valve is driven by the mechanical transmission mechanism to implement rapid closing, normal opening and closing and test control. The high-pressure oil cylinder can be fixed on the valve stem or directly used as an actuator. The surplus hydraulic oil is returned to the hydraulic oil station, so that the pipeline system can control several valves connected in parallel with one oil inlet pipe and one oil return pipe.