Fugitive dust, a physical factor commonly encountered in battle, would interact with the tail gas of armored vehicles during the diffusion process to affect infrared characteristics of tail gas and infrared detection probability of vehicles. However, limited information exists regarding the impacts of fugitive dust on infrared signature of tail gas. The gas-solid two-phase coupled flow and thermal infrared transport model was developed to comprehensively study the infrared characteristics of coupling phenomenon between dynamic dust and high-temperature tail gas, which considers the gas-solid coupled flow and heat transfer as well as the particle emission and scattering. The characteristics of coupled infrared caused by vehicle-induced dust were studied, along with the effects of particle physical parameters (i.e., particle size and concentration) on coupled infrared and the intrinsic mechanisms. Additionally, validation experiment was performed to validate the findings in the simulation results. The results show that (1) the coupling phenomenon can significantly enhance the infrared brightness and detection area of tail gas, especially in the 8–14 μm waveband; (2) the coupling phenomenon has different effects on the infrared signature of exhaust gas in different wavebands owing to the different proportions of particle radiation and gas radiation in the total radiation in different wavebands; and (3) the sensitivity of coupled infrared to particle size parameters and concentration parameters is also different, which is related to the spectral radiative physical parameters of dust particle components.