This paper analyzes the correlation between soil moisture data and different spectral data transformation, and it reveals that the correlation coefficient of soil moisture is highest near 584 nm, 711 nm, 1,055 nm, 1,420 nm, 1,635 nm, 2,176 nm, and 2,257 nm. The highest correlation coefficient can be up to 0.83206. Multiple regression analysis can be done to understand the correlation between the two, find out the reflectance values at the above fixed spectrum through a bilinear correlation, and quantitatively invert soil moisture in the study area, shedding new light on soil moisture in this large area.