In the multi-UAV coordinated power inspection task, the existing path planning methods generally ignore the impact of signal quality, which makes it difficult to be effectively applied in a wide range of power inspection tasks. Therefore, aiming at the problem that the detection effect is degraded due to the limited communication, this paper proposes a path planning method for multiUAV cooperative power inspection under 5G signal constraint. Firstly, based on the 5G signal transmission characteristics, a propagation loss model for power inspection in large scale space is established. Then, based on the genetic algorithm architecture, a path planning method for multiple UAVs is proposed, which integrates the constraints of 5G signal quality, flight mileage and patrol objectives. Finally, the path planning method of multiUAV cooperative power inspection based on 5G signal is simulated and verified. The results show that, compared with the traditional methods, the flight length of the path with poor signal quality after the constraint is reduced by 45.2%, and the vehicles will give priority to the tower with strong signal when the distance difference is small, thereby improving the detection effect of the patrol task, so as to ensure the use in a wide range of environments.