In order to improve the accuracy of the evaluation of the operation status of the switchgear, a switchgear fault identification method based on the optimal characteristic quantity of multiple types of data is proposed. Based on the real-time monitoring of various types of switchgear electrical quantities and non-electrical parameters, the principle of minimum redundancy and maximum correlation is adopted to process the collected switchgear operating parameters to obtain feature samples, and optimize them to obtain the optimal feature subset; The distance method compares the real-time monitored operating state characteristic quantity with the standard setting sample to determine the fault state of the switchgear. Practical tests and analysis of calculation examples show that the proposed method can effectively improve the accuracy and efficiency of fault identification.#$NLKeywords：Electrical switchgear, Condition assessment, Mahalanobis distance method, Fault identification