Abstract: Taking a 363 kV tank circuit breaker as the research object, the three-dimensional solid model is built according to the design drawings, and the seismic response spectrum with the seismic level of AG5 is applied to the model by using Ansys Workbench software for finite element analysis, and the simulation results under the combined condition of seismic loads are obtained. The structure is optimized and the seismic performance before and after optimization is compared and analyzed. The results show that the optimized tank circuit breaker can meet the seismic performance requirements of AG5 level, strengthening the support is beneficial to increase the natural frequency of the tank circuit breaker structure. After structural optimization, the stress level of the main components is reduced, and the maximum displacement response of the top of the bushing decreases from 90.072 mm to 66.342 mm, which is more favorable to long-term safe and stable operation of tank circuit breaker equipment.