The civil aviation aircraft engine was studied in this paper

and the performance reliability of the engine was also studied by use of performance degradation theory.Firstly

by analyzing the performance degradation process of the engine

the time-varying performance degradation model based on state space method was built

and the performance trends were predicted by using Kalman filtering.Then

considering the correlation of multiple performance parameters

the real-time performance reliability prediction model was developed by using stochastic process theory to predict the degradation time of engines.These models were applied to practical situations.It shows that the proposed methods are feasible and the prediction accuracy meets the needs of the project.Also

it provides a foundation for scientific management of engine fleet of airlines.