The embodiment of the utility model provides a fault location device for a gas-insulation closed switch, and the switch comprises a plurality of closed air chambers, wherein the air chamber with a fault of breakdown is taken as a fault air chamber. A system comprises an analyzer and a plurality of detection locators, where the detection locators are distributed on the housings of the air chambers. Specifically, the detection locators are used for collecting an ultrasonic signal of the housing of the fault air chamber when the fault of breakdown happens. The ultrasonic signal and the position information of the air chamber corresponding to the ultrasonic signal are transmitted to the analyzer through a wireless network. The analyzer is used for screening out the ultrasonic signal of the fault air chamber from the ultrasonic signals of the housings of all air chambers, and determining the position of the fault air chamber according to the position information of the fault air chamber corresponding to the ultrasonic signal.