Abstract: In the field of building energy conservation, solar energy is a highly favored clean energy. However, the instability and discontinuity of solar energy greatly affect its application effect. Phase change energy storage technology is widely used in solar energy storage technology because of its huge latent heat and constant temperature during phase change. To summarize the application effect and research status of phase change energy storage technology in the field of solar energy storage, this paper reviews the research progress of solar energy storage tanks based on phase change energy storage materials (PCM) at home and abroad. This paper focuses on the research progress of PCM packaging technology from the aspects of geometry packaging and microcapsule encapsulation. The improvement of material thermal conductivity, the improvement of supercooling and phase separation problems, and the improvement of material cycle durability are summarized and analyzed. This paper summarizes and analyzes the existing researches on the structural optimization design of solar thermal storage tanks, stratification of solar phase change energy storage tanks, storage performance of solar phase change energy storage tanks, operation strategy of solar phase change energy storage system, and performance improvement of the solar heating system by phase change energy storage tank. The advantages and disadvantages of solar energy storage tanks based on PCM energy storage in the application are summarized. Finally, the research idea of improving the performance of solar phase change energy storage tanks is put forward. Firstly, it is suggested that further research should be carried out on the encapsulation technology and heat transfer enhancement technology of composite phase change materials, and the economic problems of phase change material preparation should be fully considered. Secondly, the problem that PCM cannot completely melt or solidify during heat storage and release should be studied in depth to further improve the energy release performance of the heat storage tank. Thirdly, the structural optimization design and operation strategy optimization of solar phase change energy storage tank should be carried out. Finally, to further explore the application potential of solar phase change energy storage tank, it is necessary to develop a multi-energy coupled heating system based on solar phase change energy storage tank, study the cascade utilization of various energy sources such as photothermal, photoelectric and electromagnetic heat, and improve the stability and energy conversion efficiency of the multi-energy coupled heating system. This study aims to provide help and reference for the further research and application of solar phase change energy storage tanks.