An in vivo method for measuring the depolarization characteristic of human tissues based on polarization-sensitive optical coherence tomography is proposed. Human finger nails are used as samples. Stokes vector and the macroscopic Mueller matrix measurement methods are adopted to obtain images of different depolarization parameters of nails. The advantages and disadvantages of these two methods are measured by comparing the images. In the images generated by the Mueller matrix-based method, the nail bed structure can be clearly distinguished. It has high contrast, but with showing less structure clearly. In the Stokes vector-based method, the depolarization uniformity values obtained by different irradiation polarized light at the same position are different. The 45° polarized light is selected to calculate the circular polarization of its backward reflected light which derives the structural information of the sample, including the nail plate, the nail bed and the dermis under the nail matrix. The circular polarization measurement method based on Stokes vector incident 45° polarized light has a small amount of calculation, and extracts the most structural information, and the imaging effect is the best.