As a renewable resource and clean energy, solar energy is more and more widely used in the heating of swimming pool water. It can be used not only for the heating of circulating water in swimming pool, but also for the heating of bathing water in swimming pool. In view of the heating of circulating water in swimming pools, the direct heating system was first adopted in China. In recent years, the development of the indirect heating system has gradually been preferred. However, with the introduction of a number of new direct heating technologies and systems abroad, more and more direct heating methods have been used for the heating of circulating water in swimming pools. This paper compares the advantages of the two heating methods, and concludes that the direct water heating method is superior to the direct water heating method. The heat system is more suitable for the heating of circulating water in swimming pool.