In order to solve the problems of power system transmission line tower grounding device, such as serious corrosion, poor stability, short life, etc., the optimization scheme for grounding system in different environments is proposed when choosing the 500 kV transmission line grounding grid model as the research object. Based on the grounding material type and layout form of grounding grid, the CDEGS software simulation is used to analyze the effects of different types of soil and ground network area on power frequency grounding resistance and impulse grounding resistance of galvanized copper, copper clad steel material. Resistance reduction modes are analyzed by CDEGS, and optimization measures of reduction in resistance under different soil conditions and ground network area are proposed. Finally, the conclusion of this paper is verified by experiments, which have important practical significance for the operation of transmission line tower grounding devices. This work is supported by National Natural Science Foundation of China (No. 51507122)