In the case of certain parameters for concentration and temperature profile, particle and radiation properties of gas, the finite volume method in body-fitted coordinates is used to calculate the infrared spectral properties of the solid rocket exhaust plume with anisotropic scattering particles, results of which are compared with those of discrete ordinate method. Apparent spectral radiative intensities at 2.7μm and 2.95μm and band radiative intensity within 2.7～2.95μm are analyzed. Furthermore, the errors caused by isotropic scattering or no scattering approximation to non-linear anisotropy scattering model are investigated.