Abstract: The combustion process in the combustion light gas gun chamber was numerically simulated by using the computational fluid dynamics method. And the influences of the different factors on the interior ballistic characteristics of the combustion light gas gun were analyzed and these factors included ignition point amount, ignition energy, initial temperature and initial pressure. The results show that a reasonable ignition point amount, a reasonable initial temperature and a reasonable initial pressure can be adopted to effectively control the hydrogen combustion process and reduce the pressure oscillation in the combustion chamber. The simulated results can provide an important reference for controlling the combustion process in the combustion light gas gun chamber.