In this paper, the infrared radiation characteristics of the gas-solid two-phase exhaust plume containing solid particles are simulated and modeled. The ray tracing method is used to calculate the radiation intensity and radiation suppression rate of the exhaust plume. The simulation environment of the exhaust plume flow field and the imaging simulation scene of the air-based infrared camera are designed. Through the mechanism of solid particle radiation suppression, the particle diameter, particle flow rate, and particle complex refractive index are determined as the main influencing factors of the radiation suppression rate. Simulation calculation results show that reducing the particle diameter and increasing the particle flow rate can enhance the radiation suppression ability of the solid particles. Increasing the particle absorption cross-section can enhance the radiation suppression ability of solid particles in the gas absorption waveband, and at the same time reduce their radiation suppression ability in the non-gas absorption waveband. In some cases, the solid particles may increase the radiation intensity of the exhaust plume and change the spectral radiation characteristics.