Yunnan is located on the plateau, with strong ultraviolet radiation and sunshine. The radiation of the sun can not heat the air, but it can make the soil warm. During the day, the temperature of the ground layer is determined by the temperature of the soil and the cooling of the night. Therefore, combined with the influence of geographical climate such as topography, monsoon, sunny seasons and forests in Yunnan, it is shown that the functions of lateritic soil in solar thermal energy are relatively insufficient, and the red soil is easy to cool at night, thus forming a special climate characteristic of "great difference in temperature in Yunnan", and also affecting the annual temperature difference.