The utility model provides a bus support insulator, which is suitable for GIS (Gas Insulated Switchgear) or GIL (Gas Insulated Switchgear) equipment, and is characterized by comprising a shell of theGIS or GIL equipment, a bus of the GIS or GIL equipment and a bus support insulator body, wherein the bus support insulator body comprises epoxy resin impregnated paper, a voltage-sharing electrode, an electrode protection layer and a creepage-increasing umbrella skirt; the bus support insulator body is provided with a plurality of layers of epoxy resin impregnated paper. The voltage-sharing electrode is arranged between any two layers of epoxy resin impregnated paper; the epoxy resin impregnated paper and the voltage-sharing electrode are wound on a bus of the GIS or GIL equipment; the epoxyresin impregnated paper and the voltage-sharing electrode are coated by the electrode protection layer; and the outer side surface of the electrode protection layer is provided with a plurality of layers of annular creepage-increasing umbrella skirts, so that the creepage-increasing umbrella skirts can effectively increase the creepage-increasing dry arc distance of the insulator and avoid creepage flashover of the insulator.