In the field of lunar surface content analysis, spectral characteristics of the 2.2~3.2 μm waveband can provide a strong basis for analyzing and identifying specific compositions. For lunar soil, an object’s spectrum in this band includes not only reflective solar radiance, but also emissive radiance from the temperature characteristics of the object itself. These form a mixed spectrum, which complicates the spectral analysis for this band. Based on a mixed spectral model, considering both reflective and emissive radiance on the lunar surface, spectral characteristics for a 2.2~3.2 μm waveband are simulated and relationships are analyzed between reflective/emissive spectra and factors such as temperature, light, an object’s physical composition, etc. Moreover, a simulative platform (incorporating a spectrometer, light source, temperature controller, and simulative object) is developed according to lunar surface conditions, so as to further validate the mixed spectral model, which may provide a reference for lunar surface spectral analysis and the development of spectrometers.