Abstract: To study the influence of the asphericity degree on droplet particles optical properties in different gravity fields, the optical properties of water droplet with equal volume and different aspect ratios in the wavelength between 3.0 μm and 5.0 μm were calculated. It was found that although the changing trend of the optical properties of the water droplets with wavelength is very similar, their specific values significantly depend on the spatial orientation and the asphericity degree of water droplets. In general, the absorption cross section of water droplets strongly depends on its aspect ratio only when the azimuth angle θ is small and the wavelength is short. In contrast, the scattering cross section, asymmetry factor, and scattering phase function depend on the aspect ratio of water droplets at any azimuth angle and wavelength. Therefore, because the optical properties are strongly dependent on the aspect ratio of the droplet particles, the radiation transmission properties of fog composed of water droplets should exhibit different results in different gravitational fields.