A performance analysis model of pulse detonation engine with convergent-divergent nozzle was established.By using detonation transmission analytical solution of characteristic method and processing method of homogeneous state of detonation chamber,the exhaust process through the nozzle after the detonation wave arriving the exit of detonation chamber or the contact face of purge gas was simplified to a fixed exhaust volume zero dimensional model.Compared with the experimental data,the model developed can be used for evaluating the engine performance trend of different nozzle sizes.Through applying some curve fitting,the model can be used for calculating the engine performance at different regimes.