Vacuum circuit breaker as a substitute for SF6 circuit breaker development direction is receiving widespread attention, in order to improve the high voltage level vacuum interrupter insulation level and improve the current capacity of the vacuum interrupter under the large rated current, this paper proposes a 126 kV self-voltage sharing vacuum interrupter new structure, the structure through the coaxial arrangement of ring ceramic voltage-sharing capacitors in the interrupter for the outside to achieve the effect of voltage-sharing of the vacuum interrupter shielding, and at the same time, can increase the effective heat dissipation area of the interrupter. The effective heat dissipation area of the interrupter can be increased. Establish the 126 kV vacuum interrupter model, electric heat field simulation analysis. The study shows that the self-voltage sharing vacuum interrupter can reduce the maximum internal electric field strength by 14.9%, and at the same time reduce the maximum internal temperature rise by 15.5K, which provides a basis for the development of vacuum interrupters of 126 kV and above voltage levels.