OH radicals in atmosphere, an important mediator of the photochemical reactions between various atmospheric compositions, play a key role in the formation and transformation of other atmospheric components. Based on the OH concentration spatiotemporal database constructed by MLS global observation results of OH, and the OH emission spectra database from Lifbase, SCIATRAN was modified according to the radiation transmission theory. The simulated image of spatial heterodyne spectrum (SHS) detector was obtained in the state of limb scanning and the contribution of atmospheric OH radical fluorescence emission in observing energy was extracted. Based on the radiation transmission theory, the quantitative influence of the uncertainty of each parameter in the simulation process was analyzed quantitatively. The results can not only provide scientific theoretical supports for the construction of detector for mesospheric OH radical, but also provide the basis for the design of relevant parameters of detector.