In order to solve the problem of fast collection of point for power line inspection with banding area, a multi-modal LiDAR is designed, where asymmetrical scanning model is realized to improve the efficiency of point cloud collection. The newly presented multi-modal LiDAR takes advantages of double optical wedges scanning unit whose utilization rate of laser pulse can reach as high as 100%. Double optical wedges are driven by servo DC motor whose rotating velocity and rotating position can be accurately controlled. It offers the advantages that the scanning trace can be controlled for different model, especially an asymmetrical scanning model of regional point cloud multiplication is realized to improve the collection efficiency of zonal point cloud. Data collection by flight and automatic inspection of power line by UAV are presented using the designed LiDAR. The vertical takeoff and landing (VTOL) UAV is applied to data collection test. The dense point cloud is collected by LiDAR, automatic inspection of power line is presented using DJI Phantom 4pro. The multiplicity of point location of DJI Phantom 4pro is evaluated. The results show that the density of point cloud collected by the designed multi-modal LiDAR which carried by the VTOL UAV with flight velocity of 25 m/s can reaching as high as 146 pts/m2. The efficiency of data is improved more than 4 times compared with the efficiency of LiDAR with traditional scanning ways. Multiplicity of point location of DJI Phantom 4pro for automatic inspection based on point cloud can reach 0.15 m, meeting the requirements of UAV precision operation.