This type of vacuum switch adopts primary sealing and discharging process, ceramic insulating shell and CuCr alloy contact material, which has the advantages of high insulation level, low current cutoff value, strong arc extinguishing ability, long service life, small volume, safety, no pollution, low noise and simple maintenance. Matched with corresponding vacuum contactors, it is widely used as electrical equipment for control and protection of power transmission and distribution systems in electric power, machinery, chemical industry, metallurgy, mining and railway departments.