The fast capture, alignment and stabilization tracking system of free space beam is the key module to ensure the establishment of atmospheric laser communication link and stable communication, and the distorted spot center location technology in turbulent atmospheric channel is the key link to provide accurate and stable feedback. In order to improve the stability of communication link, a sliding weighted centroid location algorithm is proposed to solve the problem of poor location stability of traditional algorithms such as barycenter method and centroid method in atmospheric laser communication. The adaptive threshold segmentation method is improved to improve the accuracy of spot location. Background noise removal and center noise compensation were carried out to preserve the effective gray range of spot to the maximum extent. By improving the threshold segmentation method, the accuracy of spot center location can be improved. Background noise removal and center noise compensation were carried out to preserve the effective gray range of spot to the maximum extent, and the sliding compensation mechanism is added to the nonlinear weighted centroid location algorithm, which can reduce the location error caused by spot scintillation drift in communication, improved spot location stability and accuracy. Gaussian beam passing through atmospheric turbulent phase screen is simulated to generate distorted light spots of different intensity, and the sliding weighted location algorithm is verified theoretically, and the continuous light spot image generated by experiment is verified experimentally. and the results show that, Compared with the traditional barycenter method, centroid method and nonlinear weighted centroid method, the sliding weighted centroid location algorithm proposed in this paper can reduce, the proposed sliding weighted centroid localization algorithm proposed in this paper can reduce the step distance of continuous spot center localization to different degrees, which can be reduced by 21.5% in theoretical results and 11.7% in experimental results. In addition, the total intensity of pixels in the spot center mask of the same area is higher and the comprehensive positioning effect is better.