The functional properties of nanomaterials are closely related to their particle size and morphology. Image dynamic light scattering is a fast, accurate, non-contact method for measuring nanoparticles. Combining image dynamic light scattering with polarization scattering, a method for measuring the morphology of non-spherical nanoparticles was proposed. Theoretical analysis showed if the incident light was vertically linearly polarized, the scattered light at different polarization direction related to the shape of measured particles. A polarizing camera was used to measure the dynamic light scattering signals of spherical and non-spherical particles at 0° (vertical direction), 45°, 90° (horizontal direction) and 135° at 90° scattering angle. The results show that the degree of linear polarization of spherical particles is close to 1, that of octahedral particles is slightly less than 1, and that of rod particles is less than 1. The degree of linear polarization of non-spherical particles such as nanoplates and nanowires has been reduced to different degrees. The linear degree of polarization was defined as the optical sphericity to characterize the particle morphology. The particle morphology distribution of nanoparticles can be rapidly measured by using the polarization image dynamic light scattering method.