In order to improve the usability of military electronic equipment, the maintainability prediction method is studied. Explore the maintainability physical model and mathematical model, analyze the characteristics and application of the commonly used maintainability prediction methods. On this basis, put forward the prediction idea about mean time to repair of organizational-level, and summarize the mean repair time prediction process, which meets the engineering demand and has strong operability. Then the application analysis is carried out by example. The results show that the method can guide designers to predict the equipment’s maintainability index more accurately, and provide support for maintainability design.