In the study of water transport in root zone, the coupled model of soil water and heat is usually used to describe and predict soil water transport quantitatively, and the root water uptake model is used to simulate the process of root water uptake. With low pressure, low oxygen, strong radiation, and frequent exchange of cold and heat in the surface layers and thin soil layers, soil water transport in surface soil is complex and crop growing is affected by water and heat greatly. The root water uptake, energy transfer and substance migration are affected by hydro-thermal combination remarkably. In order to further explore the principle of hydro-thermal migration in the root zone and understand the characteristics of root water uptake in Tibet, the studies about model coupling soil water and heat and model of root water uptake in China and abroad are reviewed. In view of the unique hydrothermal conditions in Tibet, it is suggested to combine the coupled model of soil water and heat with the root water uptake model to build a root water absorption model considering the hydro-thermal coupling factors, so as to better adapt to the local reality and reveal the root soil water movement law.