Current point cloud intensity correction is confined to single scan station. In order to solve this problem, we propose a histogram equalization method for multi-scan intensity based on Gaussian mixture model. Firstly, the range-intensity and incidence angle-intensity correction models are used to correct the intensity for a single scan station. Then Gaussian mixture model is used to fit the histogram of intensity distribution after correction and segment the histogram. Finally, normalization of multi-scan intensity is achieved through sub-histogram matching. The experiment results indicate that the proposed method can not only correct the intensity of a single scan station efficiently, but also improve the inconsistence among different scan stations.