Abstract: For 3D point cloud generated by LiDAR scanning electric power system,vertical projection and histogram were made to convert the cloud into 2D gray image which has even grids．Some highest histogram bins were determined as the horizontal position of electric towers．The towers were separeted and meanwhile the lines were dirvided into seve-ral segments along their stretching direction．For each segment,projection was made along the normal direction of its pendent plane．Iterative robust quadratic fits were made on the projected points to divide them into different layers from the top down．Extraction of towers and fit of lines are important for spatial distance check,incarnation of lines point cloud and scene roam.

Key words: LiDAR,3D point cloud,Tower positioning,Transmission line fitting