The analytical model was developed using the water hammer and one-dimensional fluid transient theory.The combustion time delay was considered.All system parameter changes during the propulsion system engine starting process were considered.The characteristic method and the classical Runge-Kutta method were adopted for simulation.The simulation results are consistent with experiments.The results show that these models give reasonable descriptions for water hammer and flow oscillation during engine starting process.The simulation methods meet the accuracy requirements and could provide guidance for designs and experiments of propulsion system.