Abstract: A new aerial-ground integrated long-distance strip topographic surveying method, based on UAV oblique photogrammetry and vehicle laser scanning technique, is put forward to solve the problem of insufficient accuracy of long-distance strip topographic map of UAV surveying in alpine and canyon area. First, three main problems in UAV surveying for strip topographic map in alpine and canyon area were summarized, including insufficient control points and uneven distribution, inadaptation of traditional aerial triangulation method to oblique photography, difficulty of UAV point cloud non-terrain noise filtering. The corresponding solutions were proposed respectively. Then, based on these solutions, a complete strip topographic surveying method in mountain valley area was proposed. The experimental results show that the bandwidth of the strip topographic map can be guaranteed by UAV oblique photogrammetry. Moreover, the accuracy of the topographic map is further improved by introducing the vehicle laser scanning technique and could meet the demand of generating large scale topographic map for engineering project.