Aiming at the complex problem of thermal fault feature extraction and digital representation in the infrared image diagnosis of power equipment, a multi-attribute fusion thermal feature digitization method for power equipment is proposed in this study. The method uses heat power equipment fault features and diagnostic files related to research analysis, based on image preprocessing, to extract the images of key areas with high temperatures, heating area, location, and thermal property values, such as hot clustering, building a multiple-attribute information fusion of overheating fault feature vectors to realize a digital description of the thermal fault characteristics. A circuit breaker is used as an example to verify and analyze the proposed method. The results show that the proposed method can effectively describe the typical infrared fault spectrum, and can be used in the intelligent classification and diagnosis of equipment faults in the case of a large number of complex fault samples.