Disclosed is an anti-pollution flashover method for a high-voltage line insulator. By adoption of the method, four kinds of measures are adopted to prevent from accidents specific to multiple pollution flashover inducing factors: a, the leakage distance of the insulator is prolonged by increasing the number of insulator sheets in each single-phase insulator string; b, the creepage distance of the insulator string is prolonged by gluing anti-pollution flashover covers on the edges of partial insulators in the insulator string; c, a high-voltage wire with the insulator string in a suspension manner is additionally provided with an insulating sheath so as to realize effective isolation between the insulator string and the high-voltage line; and d, the high-voltage wire and the insulator string are connected through an insulating suspension wire clamp, so that the voltage tolerance level of the insulator is lowered. By combination of the four kinds of anti-pollution flashover measures, the creepage distance of the insulator string is greatly prolonged, the voltage tolerance level of the insulator is lowered, and a conductive path cannot be formed by the water-soluble dirt on the surface of insulator, so that the accident of insulator pollution flashover can be prevented effectively, and safety of the electric power system and power consumers are ensured.