Abstract: To solve the problems in high-voltage transmission line inspection,such as fixed-wing unmanned aerial vehicles（UAVs）are incapable of fine inspection and multi-rotor UAVs move slowly and require remote pilot which may pose safety risks,a scheme for inspecting high-voltage transmission lines with multiple cooperating autonomous multi-rotor UAVs is proposed.A cooperative method is discussed for inspecting high-voltage towers and transmission conductors by deploying two networked UAVs at both sides of the power line,respectively.Machine learning and multi-agent consensus control algorithms are employed to design the autopilot controller for the UAVs.According to the above work,four four-rotor UAVs and a ground station are built to validate the proposed methods.In the experiment,two pairs of UAVs are deployed to inspect the high-voltage transmission line in parallel with each other.The result shows that the UAV-station system can finish the inspection work as expected,and are free from misreported defects.Compared to the single remote-pilot multi-rotor UAV when inspecting high-voltage transmission lines,the two-UAV cooperation scheme features autopilot,and the average speed of inspection is even higher than the maximal speed of single UAV.Moreover,the average time of inspecting a transmission tower is less than half of single remote-pilot UAV’s.