Aiming at the problem that remote sensing data of detection band of infrared early warning satellite(IEWS) is difficult to obtain, the earth background radiation simulation method of IEWS detection waveband based on retrieving earth surface temperature was studied. The earth surface temperature distribution maps were generated by using a generalized single-channel algorithm for retrieving earth surface temperature of the FY-3/MERSI datasets. On this basis, the earth infrared radiation model was constructed, which fully considered the influence of altitude, atmospheric model, surface type and other factors on earth surface radiation. The joint programming of MATLAB and MODTRAN was used to calculate the surface radiation corresponding to each pixel, and realize the generation of earth background radiation image of IEWS detection band. The simulation results show that the simulated images have high resolution, and can accurately reflect the earth background radiation characteristics of IEWS detection waveband. The research result provides scene data support for studying IEWS operational effectiveness evaluation and target recognition technology.