The invention discloses an energy-saving system for power matching between an engine and a hydraulic pump. The energy-saving system comprises a pressure sensor, an electronic load controller, an energy-saving controller, an accelerator potentiometer, an optical-electricity encoder, an actuating mechanism, a proportional electromagnetic valve, a pressure relay, an engine oil pump, the engine, a variable pump, a variable mechanism and an oil tank, wherein the oil tank is respectively connected with the engine oil pump and the variable pump, the engine oil pump is respectively connected with the accelerator potentiometer and the engine, and the engine is coaxially connected with the variable pump and is used for driving the variable pump to operate; the optical-electricity encoder is arranged on the engine; the variable pump is synchronously connected with the actuating mechanism, the pressure relay and the variable mechanism, and the proportional electromagnetic valve is arranged on the variable mechanism; the accelerator potentiometer and the proportional electromagnetic valve are respectively and electrically connected with the energy-saving controller; the optical-electricity encoder and the pressure relay are respectively connected with the electronic load controller, and the electronic load controller is connected with the pressure sensor; the variable mechanism is used for controlling the rotating speed of the variable pump.