Method and system for cruise control for pure electric vehicle

The invention discloses a method and system for cruise control for a pure electric vehicle. The method comprises the following steps: receiving a constant speed cruising request sent by a driver; after receiving an effective constant speed cruising request, judging if the whole vehicle state meets a constant speed cruising working condition according to a sensor signal of the whole vehicle; if the whole vehicle state allows to enter the constant speed cruising working condition, entering the constant speed cruising working condition and recording a rotating speed of a motor at the moment of entering into the constant speed cruising working condition; and controlling a motor controller to realize the constant speed cruising according to the rotating speed of the motor. By utilizing a rotating speed control method of a motor control system, the complexity levels of a control method and a control scheme are reduced, the calibration workload after the control scheme is made is reduced, and the cruise control for the pure electric vehicle is more effectively performed. Besides, a zero torque mode instruction is sent to the motor controller by a whole vehicle controller, and after a feedback torque as 0 is received, a motor rotating speed mode instruction is sent, so that the safety and the comfort level of the whole vehicle are ensured.