After the die casting machine adopts the servo drive system, the system pressure and flow loop, the hydraulic system supplies oil according to the actual needs of the flow and pressure, overcoming the high energy consumption caused by the high pressure overflow of the ordinary quantitative pump system. The hydraulic machinery can operate according to the set pressure and flow (speed), such as the motor of the die casting machine works according to the set speed in the high flow stage of the opening and closing die, injection and so on. In the pressure holding, cooling, intermittent action and other stages can reduce the speed or even stop, so that the actual energy consumption of the oil pump motor is reduced by 40-70%.