Due to the limitations of design specification，the distribution network has low insulation level and weak lightning protection ability． With the application and promotion of composite insulation materials in 10 kV distribution network，through the comparison of the characteristics of insulation crossarm and conventional lightning protection measures，the excellent protection ability against lightning flashover and power frequency continuous current of insulated crossarm can be realized to significantly improve the lightning protection ability of 10 kV transmission line． In order to further reduce the occurrence of lightning tripping or wire breaking accidents in 10 kV distribution network，a comprehensive lightning protection system of section distribution network based on insulated crossarm and combined with conventional lightning protection measures is proposed to realize multi － level and three － dimensional lightning protection system．