Taking LUDV hydraulic system of an electric excavator as the research object, from the perspective of reducing overflow loss and improving energy saving, combined with the good speed regulation of asynchronous motor, a flow matching method of hydraulic system was introduced. The pump and valve synchronous control mode was applied to hydraulic system, the pressure drop of multichannel valve was set at 1.4 MPa, the handle signal was used to control the speed of fixed displacement pump and the flow area of LUDV multichannel valve at the same time. The flow rate mathematical model of the excavator working mechanism was established. The AMESim simulation results show that: when the excavator takes single or compound action, the pump output flow rate is almost equal to the expected value, the pump outlet pressure is higher about 1.4 MPa than the maximum load sensing pressure; when the pump flow rate is saturated, the pressure drop decreases, and the flow rate of each actuator is proportional to the demanding flow rate without interference.