In the paper, a nine-index evaluation method of soil corrosive property to grounding grid is established based on analysis of soil physical and chemical properties in 120 transformer substation test stations, inspection of index corrosion condition about soil corrosion to buried metals as well as the test results of influence of soil temperature, water content, pH value, chlorine ion content, sulfate ion content and other factors on metal corrosion. The method is simple and practical, comprehensive influence factors are considered, the accuracy is high, thereby providing scientific basis for surveying and designing newly-established transformer substations, and monitoring corrosion of transformer substation grounding grid in operation. Two factors of air capacity and regional annual average temperature are included into the evaluation method for the first time in China, and the evaluation method of galvanized steel and copper grounding grid is proposed for the first time according to the nine-index evaluation method determined in the paper.