Abstract: Gas insulated switchgear (GIS) cable terminal is widely used in high-voltage cable system. In recent years, many failures caused by low temperature have occurred in cable terminals in winter, and the insulation interface is one of the main reasons for the failure of cable GIS terminals in extremely cold environments. This paper is based on the faults of two interfaces inside the cable GIS terminal. The GIS epoxy casing simulation sample was prepared for the epoxy bushing/rubber interface, and the mechanical properties test and stress field finite element analysis were carried out at –40 ℃. In view of the failure of rubber/XLPE interface, the interface sample was prepared and the breakdown test was carried out under different temperature and roughness conditions. The results show that when the temperature of epoxy casing drops suddenly, the internal stress at the metal insert nut will increase or even exceed its bending strength. The shrinkage of silicone rubber will cause an air gap at the epoxy casing/rubber interface, which may lead to the breakdown of the casing. Temperature cycling at low temperatures is one of the main reasons for the failure of rubber/XLPE interface at GIS cable terminal in extremely cold environments. The analysis results in this paper can provide a basis for GIS cable terminal design and maintenance in extremely cold areas.