Large-scale water conservancy projects in the southwest of China monitor frequent seismic events during the cyclic reservoir impoundment process, which poses a certain threat to the safety and stability of the neighboring transmission corridors. In order to study the impact of reservoir earthquakes on ultra-high voltage transmission towers, this paper is based on the target response spectrum of reservoir earthquakes derived from the seismic statistical law since the water storage in Baihetan reservoir area, selects the reservoir earthquake records that conform to the law from the Pacific Ocean Seismic Network, and adopts the finite element method to study the mechanical response of the transmission towers under the reservoir earthquakes. On this basis, carbon fiber reinforced composite materials are used to reinforce the tower for the weak position, and the reinforcement effect is analyzed. Calculation results show that: under the reservoir earthquake, the weak positions of the tower appear in the middle of the tower body and the tower legs; under the maximum seismic load of reservoir earthquake of magnitude 6, the tower remains stable and there is no failure of the rods, etc.; applying different directional loads to the tower, it is found that the horizontal load has a more significant effect on the tower. For the weak position of the tower, double-layer carbon fiber reinforced composite material is used for reinforcement, and under the same working condition, the maximum displacement of the tower top, tower body and tower legs are reduced by 12.26%, 9.34% and 9.57%, respectively. The simulation results verify the effectiveness of the reinforcement measures and provide certain theoretical support for the subsequent seismic reinforcement research.