Under the two common conditions of incident natural light and linearly polarized light, we simulate the polarization degree and polarization ratio distributions of whole scattered light and various orders scattered light based on Mie theory and Debye series expansion. The results show that the scattered light is usually partially polarized when incident light is natural light. The distribution of polarization degree is consistent with Rayleigh scattering when the particle size is less than the wavelength. When the particle size is larger than the wavelength, the polarization degree of the whole scattered light is very low at the forward scattering angle, and increases with the increase of scattering angle but changes frequently, and get a high value at the rainbow angle. The scattered light is commonly elliptically polarized light when the incident light is linearly polarized light. In this case, the polarization ratios of the whole scattered light and various orders scattered light are high. A minimum value occurs only when the azimuth angle is far from 0°, 90° and 180°.