A hierarchical segmentation method for stereo images based on 3D laser scanning is proposed to address the current issue of poor hierarchical segmentation performance in stereo images. Firstly, based on a 3D laser scanner, collect 3D laser point cloud data from stereo images; Secondly, calibrate the correspondence between stereo image pixels and 3D laser point cloud data; Finally, hierarchical segmentation of stereo images is achieved through OTSU multi threshold segmentation method. The experimental results show that the average intersection to union ratio of the proposed method is between 83.6% and 92.5%, and the hierarchical segmentation accuracy of stereo images is high, the effect is good, and it is more suitable for practical applications.