In order to reduce the energy consumption and simplify the movement of the excavators, modern computer technology is available for the program control of the hydraulic power system. Meanwhile, this technology brings about electro-hydraulic proportional technology to engineering machinery. The PLC was used to control the important parts of the hydraulic power system of the excavator, all the inputs and outputs were dealt with real time then the signals were transmitted to the upper computer. Through this method, the PLC that was multi-compatibility and reliability could be used to realize the power matching of the engine and the electric-variable displacement pump.According to the installation test result, this technology can effectively reduce energy consumption.