SCIATRAN, providing more reliable simulation data for retrieval of CO2 concentration, is a high spectral resolution radiative transfer model with rich parameters and easily calibrated. In this article, SCIATRAN was used to simulate the CO2 radiation intensity of different aerosol types, aerosol optical thickness and surface types, and the regularity of influence of CO2 radiation intensity under different conditions was analyzed. The results show that: first the influence ratio of aerosol type on CO2 radiation intensity is less than 8%, because the urban aerosol has complex composition, the effect on CO2 radiation intensity is slightly larger than that of country type and ocean type aerosol; then, the influence of aerosol optical thickness on CO2 radiation intensity is -3.52%-+42.97%, and the smaller the optical thickness, the greater the radiation intensity; Last, the surface types have the greatest influence on the CO2 radiation intensity, and the difference between the result and the reference value is up to 166.43%. The CO2 radiation intensity increases when the surface albedo increases. This article also verifies the feasibility and effectiveness of the simulation signal based on SCIATRAN by comparing its analog signal to the measured signal.