A calibration device for Doppler Wind Lidar has been designed and the servo control system is the key part.The calibration system provides a high stability and a high precision speed standard.Its high resolution encoder with 131072 pulses and corresponding rotating platform with a diameter of 200 mm,has a maximum speed deviation of only 0.4 mm/s.The electronics control system implements the functions of starting,stopping,testing and speed indicating,etc.The upper computer adopts an industrial PC to communicate with the servo controller through RS-485 bus,and thus to get the current speed and other relevant data and set all parameters of the servo controller.