Abstract: Microbial aerosols, as an important component of atmospheric aerosols, can affect atmospheric radiation characteristics through absorption or scattering. At present, the research on the optical properties of microbial aerosols is mostly limited to single-band or single germplasm. It is impossible to generalize the generality and particularity of microscopic aerosol optical properties, which is not conducive to comprehensively analyze the effects of microbial aerosols on atmospheric radiation characteristics. Herein, the spectral reflectances of three eukaryotic microbe and three prokaryotic microbes in the waveband from 0.25 to 15 m were measured. Based on the Kramers-Kroning algorithm, the complex refractive index (CRI) m was calculated and the FTIR spectra of microbes were analysed. The similarities and differences between the optical properties of the 0.25-15 m band of eukaryotic and prokaryotic microorganisms were compared. The conclusion can help to comprehensively understand and quantitatively calculate atmospheric radiation characteristics, provide theoretical support for microbial aerosol remote sensing detection and type identification, and provide new ideas for the development of new functional materials.