Compound drive system and control method of electric excavator

The invention relates to a compound drive system of an electric excavator. The compound drive system of the electric excavator comprises a first motor, a second motor, a load-sensitive valve, a pressure sensor and a vehicle control unit; the first motor is configured to drive a turning device of the electric excavator; the second motor is configured to drive a hydraulic pump so as to provide hydraulic oil for a plurality of action execution elements of the electric excavator; the load-sensitive valve is in communication between the hydraulic pump and the action execution elements and can adjust the oil supply pressure and flow according to the pressure and flow requirements of the action execution elements; the pressure sensor is configured to measure the pressure of a load-sensitive oil port of the load-sensitive valve; and the vehicle control unit is in communication connection with the pressure sensor and is configured to enable the first motor to selectively work in a single actionmode or a composite acti