The invention provides an all-weather air supplementation device applicable to multi-interval and multi-leak-point GIS equipment. The device comprises an air supplementation unit which is used to supplement air for the GIS equipment during use, over one air supplementation pipe used to connect the air supplementation unit with the GIS equipment, a check valve which is fixed disposed on one end ofthe air supplementation pipe and connected to the GIS equipment during use, an air supply unit which is used to provide a supplementary air source for the air supply unit, a main connecting pipe whichis used to connect the air supply unit and the air supplementation unit in a ventilated manner, over two fans used for ventilation and heat dissipation of the air supplementation unit and the air supply unit, an air cylinder electric heating device which is used to heat an air supplementation cylinder in the air supplementation unit and an air cylinder in the air supply unit, an electric controlbox which is disposed in the air supplementation unit and used to implement master control, as well as a connecting cable used for electric connection between the air supply unit and the air supplementation unit. The device provided by the invention has the beneficial effects that simultaneous air supplementation can be realized for the multi-interval and multi-leak-point GIS equipment; the deviceis applicable to all weathers; applicability is high; and safety is high.