Abstract: Based on the theory of soil water dynamics, the principle of energy budget on soil surface, and the theory of aerodynamics, a model of coupled transfer of the moisture and heat in soilatmosphere continuum during soil freezing and thawing is established. The model is composed of two submodels, i.e., the model of soil water and heat transfer and the model of water and heat exchange between soil and atmosphere interface. The model is used to simulate the effect of winter irrigation on soil water regime in Winter. The result shows that winter irrigation is effective for water storage in soils. Moreover, the rational winter irrigation quota is analyzed.