Abstract: In order to improve the electrical resistance and mechanical srtength of the post insulator in the metal-enclosed Gas-Insulated Metal-Enclosed Switchgear (GIS), the material distribution inside the pillar insulator was designed by topology optimization method based on finite element simulation,and the electric field distribution and mechanical stress field distribution characteristics of the insulator after the gradient distribution of the relative permittivity and Young's modulus of the material were studied. The simulation results show that: after topological optimization, reasonable material parameter selection can significantly reduce the maximum electric field strength and mechanical stress at the interface formed by the insulator body and the metal insert.Compared with the initial uniform pillar insulator, the maximum electric field and mechanical stress can be reduced by more than 40% and 20% respectively,it provides a technical reference for enhancing the comprehensive performance of pillar insulators and improving the operational reliability of insulators.

    Key words: gas-insulated metal-enclosed switchgear; finite element simulation; pillar insulator; electric field distribution; mechanical stress