The invention provides a vehicle speed measuring method and device based on an electric vehicle. The vehicle speed measuring method based on the electric vehicle comprises the steps that when a motor controller of the electric vehicle cannot obtain vehicle speed information from an antilock brake system (ABS) of the electric vehicle, according to the motor rotary speed of the electric vehicle, the vehicle speed estimated value is calculated and obtained, according to the accelerated speed of the electric vehicle, the accuracy of the vehicle speed estimated value is verified, and if verification of the vehicle speed estimated value is passed, according to the vehicle speed estimated value, the vehicle speed of the electric vehicle is determined. Compared with the prior art, when the ABS breaks down, the vehicle speed information cannot be obtained, and the vehicle speed calculated and obtained through the motor rotary speed can cause the calculated and obtained vehicle speed to be inaccurate due to skidding or locking of the vehicle so that the situation that whether safety exists or not is judged by a driver according to the accurate vehicle speed information cannot achieved, and the potential safety hazard of driving operation exists; and according to the vehicle speed measuring method, the technical problem that in the prior art, safety is low is solved.