As a novel remote sensing technique, polarimetric detecting technology is a useful supplement to traditional hyperspectral remote sensing technology, which provides more information for remote sensing. By taking advantage of the polarization characteristics of the surface reflecting light of soil with different moisture, the polarization spectral method is applied to measure soil moisture. The spectropolarimeter was used to measure the polarized reflectance spectrum of different soil moisture. The correlation between soil moisture and polarization spectrum was analyzed. The polarization characteristics of soil surface reflecting light in different viewing angles were surveyed by experiments. The experimental results show that: in the higher soil moisture conditions, the polarization spectrum and soil moisture have a certain connection, especially in the 500～700 nm band and soil moisture is directly proportional to the degree of polarization; but in low soil moisture conditions, the correlation of polarization spectrum and soil moisture is not obvious; in addition, the polarization spectrum are influenced by viewing angles, for example, when the incident angle of source light is fixed at 50°, while the viewing angle of instrument is between 20° and 60°, the degree of polarization increases with the viewing angle. When the viewing angle becomes wider,, the degree of polarization changed more significantly with the soil moisture.