Grounding grid is an important device which ensures the safe operation of substation. Its corrosion is influenced by various factors and the influence of these factors is varied. It is difficult to infer the relationship between the corrosion rate and its influencing factors, so this paper apply the grey clustering method of grey system theory in the grounding grid corrosion and gives an application instance and realizes it by MATLAB. The results demonstrate the practicality and effectiveness of the method mentioned in this paper. This method can provide reference for high reliability for related departments in the implementation of emergency situation due to grounding grid corrosion.