Busbar support insulator, applicable to substation, has good characteristics of water hydrophobe, aging resistance, tracking resistance, and corrosive resistance. They have high electrical performance: Silicone rubber sheds are good in hydrophobe and have water floating capacity, heavy pollution resistance, can prevent flash over due to pollution. It can work on the severely polluted sites without special clearing. The top and bottom installation sizes can be designed same to those of porcelain post insulators.