In order to reduce the size of gas insulated metal enclosed combination apparatus, reduce the emission of SF 6 decomposition material and achieve 3060 carbon peak and carbon neutral target at an early date. The author based on Ansys Maxwell finite element simulation and equal pressure shield structure optimization to carry out the design study on the miniaturization of 252kV single-column canister type surge arrester, through the determination of the optimized equal pressure shield, to carry out the wedge gap, valve dielectric constant on the field strength, potential distribution and analysis of GIS surge arrester field strength maximum, the developed 252kV canister type surge arrester miniaturization structure successfully passed the type test. The results show that, on the basis of ensuring the internal insulation strength, the optimized uniform pressure shield after simulation calculations yielded a maximum field strength value of 14.3kV/mm inside the tank, the maximum field strength is mainly concentrated in the tank flange bending surface, the miniaturized GIS arrester volume 0.159m 3 , compared with conventional SF6 reduced by 31.7 % , to achieve the purpose of miniaturization. In addition, the simulation results show that the dielectric constant of the valve piece has no effect on the field strength change inside the tank. The paper proposes a structure optimization scheme for miniaturization of 252kV GIS arrester from the electrical performance practical, with high manufacturing feasibility and application scenarios, which provides an important reference value for the development of miniaturization of GIS arrester of different voltage levels.