The signal extraction method of wind lidar affects the accuracy and range of lidar directly. In order to improve the accuracy and rang of wind lidar , A method of gravity extraction based on Gauss fitting is designed. Firstly frequency spectrum is fitted by Gauss function. Then center of gravity frequency is calculated for the fitted frequency spectrum. Using the fixed frequency sine signal outputted by the signal source , the average measurement error of bary- center method based on Gaussian fitting is 0. 43 MHz , the average measurement error of the maximum method is 1. 54 MHz and the average error of the barycenter method is 1. 18 MHz. The measured echo signals of the wind lidar are tested. The measuring range of the wind lidar is 2 850 meters base on the Gaussian fitting method and the measuring range of the wind lidar is 2 550 meters. The results show that the measuring range of the wind lidar based on the Gaussian fitting method can improve the accuracy of the wind lidar. And increase the measuring range of wind lidar by 12. 5% 。