Using the object-oriented design method, a general, flexible and reliable aircraft engine performance simulation framework is designed. The simulation platform is divided into three layers clearly and the corresponding kind of model is established under each layer, thus the data exchanges among layers are flexible and effective. The fundament component class library is established and can be used to build different aero-engine simulation models. The performance simulation framework is applied to several calculating missions including steady, transient and real-time simulations. Based on the simulation framework, a two-spool mixed flow turbofan simulation model is build and its steady and transient progress are calculated. The calculation results are of high precision and verify the effectiveness of the framework.