Using the RFM model, the limb radiance errors of the four main atmospheric components (CO2, O3, H2O and N2O) in the radiative transfer observed by atmospheric infrared ultra-high spectral detector due to the uncertainty of the position, intensity and width of the absorption lines were simulated. Based on the statistics of molecular absorption line uncertainty code in HITRAN2016 database, the value whose uncertainty code is not less than 3 was used in radiation transmission calculation. It is found that the uncertainty of the absorption lines of different molecules has different effects on the limb radiances at different tangent heights, and the uncertainty factors play different role separately or mutually. Meanwhile, the radiance absolute and relative errors caused by the three uncertain factors of the atmospheric molecules were also simulated and calculated in four infrared bands of the detector, which provides data basis for spectral channel selection and atmospheric parameter inversion.