Synopsis: Focusing on the circulating cooling of superconducting coils, the author introduces an example of research and development that cools the coil by circulating liquid helium, gas helium, and liquid hydrogen. In order to realize more efficient cooling, the author explains a method that combines a circulation method with magnetic refrigeration and oscillating heat pipes, and a method that involves circulation with a cryofan in the state of low temperature fluid without going through room temperature.In addition, the benefits of circulating cooling are also mentioned.