Abstract: The traditional artificial power line inspection method can not meet the needs of power grid operation and maintenance.In order to ensure the safety of power grid lines,this paper applies the technology of UAV Carrying Lidar to the line inspection,and obtains the point cloud data,to extract complete power line points,reconstruct 3D power line corridors,detect the safe distance between buildings,vegetation and cross-over lines,and discover in time the threats and hidden dangers of the crossed objects to lines in the line corridors,it provides decision support for line maintenance personnel and verifies the safety,speediness and high efficiency of the Lidar line scanning technology through an example.