In order to study the hydrothermal distribution characteristics of the cutting slope of SUIDA Expressway before and after excavation, a saturated / unsaturated transient Hydrothermal Coupling numerical calculation model considering various climatic conditions is constructed by using the meteorological data of hailun station and the actual slope conditions of the project site, and the distribution characteristics of water field and temperature field before and after slope excavation are analyzed Freezing depth and different influencing factors under different working conditions. The results show that the water field changed significantly due to slope excavation, and the volumetric water content decreased significantly in mid-March, and the maximum decrease in mid-to-late December was 74.61%, accounting for 91.59% of the entire non-freezing period; with the increase of burial depth, the temperature fluctuation change lagged significantly, and the fluctuation range was exponentially decayed. The freezing depth of the excavated soil can reach 1.95 m, the maximum freezing depth of the excavated slope is 0.76 m, and the freezing ablation period is 31 days. The distribution state of the water field is different under different working conditions, and the volumetric moisture content is greatly affected by the permeability of the soil. The high volume water content will inhibit the propulsion speed of the frozen front, delay the trend of soil temperature change, and the temperature change difference under different working conditions is significantly affected by the volumetric water content.