Based on its properties of strong scattering and low energy flux, the low-temperature heat can be easily obtained from solar radiation. Solar low-temperature heat utilization is the earliest solar energy conversion means known by humans and widely applied. In the future, it will remain to be the most important means of solar application, which can be used extensively and economically. The background and theories of several main technologies of low-temperature solar thermal conversion are introduced in this paper, such as solar thermal collection, solar space heating, solar drying, solar-assisted heat pump, solar air conditioning and low-temperature solar thermal power systems. Based on the research status of various existing techniques and social needs, the future development direction of this area is discussed. The research on the low-temperature solar thermal conversion in the University of Science and Technology of China is also presented in this paper.