A method for calculating infrared radiation characteristics of the gas oxygen/kerosene (GOX/KERO) engine plume considering soot particles was proposed, first of all, the simulation of engine internal flow field was carried out, and the plume flow field was calculated using the nozzle throat as the inlet boundary of the gas and carbon particles, infrared radiation characteristics of the engine plume were calculated with the finite volume method (FVM) and the pseudo-gas theory based on the field parameters. The ignition experiment of the gas oxygen/kerosene engine was carried out, and the calculated results were compared with the experiment results. It was found that, the pressure errors between measurement and calculation of two pressure measurement points in the chamber were 1.4% and 3.4%, the temperature error between thermodynamics and calculation in chamber 2.16%, which verified the accuracy of the chamber flow field calculation model. The calculation results of the plume flow field containing the soot particles were in good agreement with that of the thermal imager, and the accuracy of method and model of plume flow field calculationwas proved. The plume infrared imaging in the 4.3 μm band of the calculation was in good agreement with that of the thermal imager, and the accuracy of method and model of plume infrared radiation calculation.