The invention relates to a soil corrosion prediction technology, in particular to a method for predicting the soil corrosion rate of metal material, which is mainly applied to the soil corrosion prediction research on regional carbon steel. The metal material serves as test material, test points are selected in an area which needs to be predicted, a test is taken according to 'Soil Corrosion Test Method of Materials' developed by a national soil corrosion test website, and simultaneously, the chemical components of the soil of all the test points are monitored, and the test cycle is 1 to 2 years; after the test, the rust of the test material is removed, after a sample is dried and weighed, the corrosion weight loss is calculated, and simultaneously, the chemical components of the soil of all the test points are calculated; a statistical method of stepwise regression analysis is adopted for regression analysis, a regression equation is established, and the soil corrosion rate of the area which needs to be predicted is predicted with the regression equation. The method for predicting the soil corrosion rate of metal material has reoccurrence, and can predict the soil corrosion of metal material.