This paper focused on the relationship of the biological tissue character and the Fast Fourier Transform(FFT) of Polarization-sensitive Optical Coherence Tomography(PS-OCT) signals,and researched the influence of the birefringence,texture and the structure of tissues on the FFT of PS-OCT signals. After describing the single-detector PS-OCT imaging theory in detail,it set up a three-layer tissue model. On the basis of the model,it simulated its single detector PS-OCT signals and analyzed the influence of different model parameters on the FFT of signals. By taking the bovine tendons and cartilages as samples,a A-scan experiment was carried out with the single detector PS-OCT system.Obtained FFT shows that the spectral shapes and relative frequencies change with the different tissue characters,such as birefringence,back scattering indexes and structures. The researches approve the ability of single-detector PS-OCT in detecting biological tissue characters.