The self-constructed optical system was employed to study soil moisture and reflected light polarization characteristics in visible and near-infrared, to discuss the feasibility of the soil moisture detection based on light polarization property in more wave bands. The study results show: in the band of 600-800 nm, soil moisture and the degree of reflected light polarization have correlation, especially when the soil moisture is more than or equal to 14% and less than or equal to 30%, the degree of reflected light polarization and soil moisture have proper linear relation. According to analysis of regression to measured data, linear model average standard deviation is less than 3%, having an advantage over the method of near infrared spectrum characteristic of 10% obtained in Ref.[5], accounting for the feasibility of the soil moisture detection on the basis of measuring light polarization in this band(600-800 nm), providing scientific basis for polarization remote sensing detection in wide-range soil water content.