Transmission lines are a crucial component for transmitting electricity from power plants to end-users, and their maintenance is of utmost importance. We propose an anti-corrosion spraying device for transmission lines, leveraging advanced unmanned aerial vehicle (UAV) technology. By harnessing the flexibility and high-altitude capabilities of UAV platforms, we can perform efficient, safe, and precise anti-corrosion spraying on transmission lines. Experimental results show that the UAV-based system reduces operation time by more than 40% compared to manual spraying, while ensuring coating uniformity with a measured improvement of over 25%. In addition, the UAV method eliminates the need for workers to climb towers, thereby markedly improving operational safety. This innovation represents a significant step forward in transmission line maintenance, extending service life and paving the way for a more reliable and efficient power distribution system.