Abstract: The special geographical environment in high altitude areas has a great impact on the selection of main electrical equipment. The insulation strength of electrical equipment is easily affected by air pressure, air density and ambient temperature. Combined with the type selection characteristics of electrical equipment, according to the capacity reduction analysis of high-altitude low-voltage electrical equipment, and comprehensively considering the withstand voltage level and action characteristics, this paper puts forward the type selection requirements of high-altitude main electrical equipment to ensure the normal operation of electrical equipment in high-altitude areas.