Abstract: A non linear dynamic mathematical model for a large liquid rocket engine has been established,which comprises normal models and fault models based on large liquid rocket engine with turbo pump system.The transient performance simulation has been performed under fault conditions according to jump input of various fault modes such as main valve fault,pipeline leakage,pipeline blockage,pump efficiency losses,turbine efficiency losses,which have occurred in previous hot fire tests or will be possible to occur in future.Adaptive Runge-Kutta method is employed to simulate.The calculated results show that the established model is accurate and reasonable.The numerical method can simulate effectively the transient performance of the faults.Simulation results are also discussed and analysed in detail.The work lays the foundation for further study on choice of fault modes,fault detection and diagnosis based on the model.