Abstract: The main radiation gas components are completely different in different propellant rocket engine exhaust plume, the gas spectral parameter database need to be built to quickly and accurately solve the infrared radiation characteristics of different propellant rocket exhaust plume using the spectral band model. A method of constructing the gas spectral parameter database and the program were proposed, based on the method and HITEMP2010, CO2 and H2O spectral parameter databases were establised with the wave number interval 5 cm-1 and the temperature interval 100 K; the model and the program were verified to be correct through comparing the calculated absorption coefficient distribution with the experimental measurements and comparing the calculated transmittance distribution with that calculated using the line-by-line method. Based on that, CO, OH, NO and NO2 spectral parameter databases were established based on HITEMP2010 and HITRAN 2012, and the transmittance distributions on different temperatures and different optical strokes were comparatively analyzed combined with the line-by-line method.