Abstract: The calculation theory of near-earth electric field of transmission line was introduced, and the simulation model of four-loop transmission line with the same tower was established through Maxwell platform to obtain the distribution characteristics of space electric field and near-earth electric field of transmission line. The corrosion rates of grounding material at different locations of transmission line substation in different voltage levels were measured by using multi-electrode coupling measurement technology, and the corrosion rates of grounding electrode in the presence or absence of near-earth electric field were also measured to study the influence of electric field on grounding electrode corrosion. Finally, the specific measures to mitigate the corrosion of grounding electrode were proposed by combining electric field effect and electrochemical analysis. The results show that the near-earth electric field was stable with intensity about tens of V/m, which could not be ignored. Due to the presence of strong electric field, the atmospheric corrosion rates of grounding material increased by nearly 80 times, and the corrosion rates of the material increased with the increase of voltage level.