Aiming at the problems of large amount of sensor information, strong correlation and serious redundancy in the process of fault diagnosis, a grey Kohonen network fault diagnosis method is proposed. Firstly, the grey correlation analysis method is used to analyze the relevant parameters of the index parameters in each state of the equipment, and the grey correlation analysis matrix under each state is established. Secondly, through the introduction of grey value, the strong and weak relationship of the correlation is quantified to achieve the purpose of eliminating the similar information. Finally, fault diagnosis is carried out through the Kohonen network. The example verification results show that this method can maintain a high fault diagnosis rate while eliminating the similar information, and at the same time achieve rapid diagnosis.