A theoretical performance analysis model of air-breathing pulse detonation engine is established in the flight regimes.It is based on single-cycle pulse detonation engine analysis model.The influence of the flight regime change on performance of pulse detonation engine was studied.The results show that the average thrust is decreased with the increase of flight altitude at given Mach number

and the influence of Mach number on thrust depends on the propulsive characteristics of inlet and detonation chamber.The effect of detonation frequency and combustor diameter is also considered in the model which is useful to the design and analysis of pulse detonation engine.