A database of radiative properties of sprays covering the wavelength range of 0.8～20μm and droplets radius range of 1～300μm was constructed. A method of combining database calls for radiative properties acquisition and spectral bands-grey assumption model for processing the non-grey characteristics of sprays was proposed. The result for dimensionless radiative heat flux calculated with the method was compared with the results obtained by this method and got by Mie theory and spectral bands model with Monte Carlo method.It was found that the method of database calls combined with spectral bands-grey assumption model can not only guarantee the calculation accuracy at an acceptable level, but also reduce the CPU time significantly.