The urban land surface's composition has a great impact on the urban heat island. In the northeast, northwest and southwest vast areas of China, there is usually a layer of relatively stable snow covered on soil, grass and other urban land surfaces. Under the covered snow, the land surface heat transfer has unique properties. It's necessary to combine the upper snow layer and the related underlying land surfaces together to consider the heat transfer. In this paper the authors took the snow cover-soil union's heat transfer as the object of study, carried out field measurements on the temperature of soil and the snow itself under different thickness of covered snow, and based on the principle of energy balance, researched the dynamic characteristics of heat transfer in the snow cover-soil union, established mathematical models, numerically simulated the temperature of the snow cover-soil union using winter outdoor conditions in Harbin. The results indicate that both the simulated values and the measured values show the similar trend, despite they have some discrepancies with each other. The models in this paper can accurately simulate the urban district temperature with snow-covered underlying surfaces during the wintertime.