GIS bus end extension device, transformer substation and GIS bus extension method

The invention particularly relates to a GIS bus end extension device, a transformer substation and a GIS bus extension method.The transformer substation comprises a transformer and a GIS bus, an end air chamber is arranged at the end of the GIS bus, the GIS bus end extension device is arranged between the end of a superior bus and the end air chamber, and the GIS bus end extension device comprises a transition cylinder; the transition cylinder is arranged between the upper-stage bus cylinder and the end air chamber cylinder, one end of the transition cylinder is provided with a first insulator connected with the upper-stage bus cylinder, and the other end of the transition cylinder is provided with a second insulator connected with the end air chamber cylinder, so that an independent air chamber is formed in the transition cylinder; a connecting conductor is arranged in the transition cylinder, a first connecting contact and a second connecting contact are arranged at the two ends of the connecting conductor