At present the main maintenance's manner in the civil aviation field is condition based maintenance which may improve enormously maintenance's efficiency and econmy. Maintenance optimal model concentrates the essence of condition based maintenance and plays an important role in reducing maintenance cost and raising profit of civil aviation corporation. The paper induced the establishing method of several models, such as Delay Time Model and Shock model, Proportional Hazards Model and Markov decision Model, and analyzed these models’ shortcoming in application and prospected their development.