Aiming at the problems of less research on the current electronically controlled positive flow excavator system, large energy loss at no-load, power mismatch between engine and main pump and poor energy-saving control effect, a co-simulation platform of excavator electro-hydraulic system based on AMESim and Simulink was built and an engine-pump constant power control method for dual variable pump was proposed. Through the simulation experiment of the prototype and the research of power matching under different working conditions, the correctness of the built electronically controlled positive flow excavator system and the effectiveness of power matching under different working conditions were verified. The simulation results show that the designed simulation model and power matching strategy perform well. In the simulation and experiment, the constant power characteristics of the pump can be guaranteed under different working conditions, engine power can be fully utilized and the power control of the engine can be realized.