The track optimization of UAV inspection of transmission tower and accessories such as fittings and insulators is a typical Traveling Salesman Problem. Due to the complex structure of patrol objects and many patrol components, using a single heuristic algorithm will cause problems such as track overlap and easy to fall into local optimal solution. Therefore, considering the characteristics of three-dimensional spatial structure of UAV track, a hybrid GA-SA optimization algorithm of UAV three-dimensional track is introduced, which combines Genetic Algorithm (GA) with strong global search ability and Simulated Annealing (SA) with fast local convergence speed. Taking the UAV inspection of 500 kV EHV AC double circuit drum tower as an example, according to the three-dimensional finite element simulation, the electromagnetic protection safety distance of UAV is 2 m. Combined with the patrol object and the location of common defects, 61 high-altitude safety hovering points are determined. GA, SA and hybrid GA-SA algorithms are used to optimize the track of UAV traversing high-altitude safe hovering points. The results show that compared with GA and SA, the iterative convergence times of hybrid GA-SA are reduced by 45.6% and 55.2% respectively, and the optimal track distance is shortened by 8.1% and 8.9% respectively, which verifies the effectiveness of the proposed method.