Abstract: The paper introduced some basic situations of lightning protection measures of inlet line of a mining area 110 kV substation, analyzed causes of lightning strike of 35 kV inlet line of the substation, namely line insulation level increased by people is mismatch with on-site insulation level and inlet line tower grounding resistance is too high, and proposed corresponding renovation measures, namely adopting difference protection measures of installation of insulator protection gap with lightning arrester and dendritic grounding device.ATP-EMTP simulation results verify feasibility of the reform measures.