Abstract: Combined with radiation transport equation, with energy source terms including laser energy absorbed by air and loss energy irradiated by high-temperature gas added to the energy equation of fluid dynamics equations set, the physical/mechanical model and computational method of laser energy deposition process in air-breathing laser propulsion are established. The phenomenon of air absorbing laser energy, the effect of plasma shielding laser and the propagation law of laser supported detonation wave can be simulated correctly by the radiation fluid dynamics computational code. The results indicate that the laser energy deposition efficiency is about 57%, and the velocity of laser supported detonation wave agrees well with the results of theory and experiment under similar conditions.