This paper investigates characteristics of polarization in non-line-of-sight (NLOS) ultraviolet (UV) communication channels based on a vectorized polarization-sensitive model of NLOS multiple-scatter propagation. The degree of polarization has been analyzed from the following factors: elevation angles, beam angle, field-of-view, off-axis angles, and baseline distance, etc. We draw conclusions that will guide the design of polarization multiplexing technology in NLOS UV communication systems. Outdoor experimentation has validated that this technology is useful to improve the data rate.