Insulators that are used outdoors can be polluted by dust, smoke, industrial emissions, etc., and a fouling layer is formed on the surface of the porcelain. The contaminated insulators flash across the surface under the action of voltage, which is referred to as pollution flash, and its flashover voltage is referred to as pollution. Flash voltage, in the dry state, the flashover voltage of the insulator is not greatly affected by surface contamination, but in the climatic conditions such as fog, dew, snow, drizzle, etc., the fouling layer on the surface of the insulator is damp, and the flashover voltage is greatly reduced. The occurrence of pollution flashover accidents may occur even under the working voltage. The pollution flashing accident is characterized by a long time. Generally, it cannot be eliminated by automatic closing. The accident is easy to expand, resulting in large-scale power outage and long recovery time. Seriously affect the safe operation of the power system.