Abstract: Aircraft plume is a kind of high temperature and high pressure gas, which will lead to strong radiation energy into the space and have a great influence on aircraft stealthy performance. To compute the infrared radiation signature of plume, firstly based on the Navier-Stokes equation and other governing equations, the characteristics of the whole flow field were calculated under the division of flow field, including the temperature, pressure and composition of each gas. Then, the band model parameters of the gases contained in the plume, such as spectral line absorption coefficient, interval density and half width, were computed by using both the Collided-broaden effects and the Doppler-broaden effects of the spectrum. Finally, by use of the Curtis-Godson approximation of non-uniform gas, the infrared radiation intensity of a rocket plume from the wavelength of 2 to 5 m was computed, and the results of simulation validate the correctness of this method.