Abstract: The 110 kV combined electrical equipment in a substation has air leakage problem. After the maintenance personnel carried out SF₆ live air supply for it, combined with the site situation, they applied a variety of leak detection technologies to find the leak point, found the cause of air leakage of the combined electrical GIS equipment and proposed a solution, which thoroughly solved the air leakage problem of the combined electrical equipment gas chamber, avoided the occurrence of equipment accidents caused by long-term SF₆ gas leakage, and ensured the safe and stable operation of the equipment.