The effect of aurora on limb infrared radiation is simulated and analyzed with the infrared radiation model of the middle and upper atmosphere. The simulation results show that when aurora disturbs the atmosphere, the limb radiance at 2.7 μm and 5.3 μm resulted from NO is significantly larger than the quiescent value. In addition, the limb radiation at 2.7 μm is not time-dependent, but that at 5.3 μm has a small time-dependent variance. Moreover, the limb radiance at 4.3 μm resulted from CO2 and NO+ has the obvious increase compared with the quiescent value, and CO2 makes it time-dependent. The radiance at 10 μm and 15 μm is enhanced with a certain amplitude because of the linkage effect from limb radiance at CO2 4.3 μm and similarly the variance is also time-dependent. The chemical reactions introduce the high energy levels of NO and NO+ and thus the radiance at 2.7 μm, 4.3 μm, 5.3 μm gets enhanced at the broad spectral bands including their baseband and hot bands. The properties from the model analysis are applied to the preliminary simulation of an observation event of limb radiation at 4.3 μm when aurora disturbs the atmosphere. The simulation results are compared with the measured data and thus the correctness of the model is verified.