Abstract: In order to obtain the heat transfer characteristics of heat pipe in molten salt,the heat transfer characteristics of naphthalene gravity heat pipe in the mixed molten salt are analyzed experimentally. The effects of the temperature of molten salt in evaporation section,the inlet temperature and the inlet flow rate of cooling water on the heat transfer performance of gravity heat pipe are investigated. The results illustrated that the naphthalene gravity heat pipe can run stably in molten salt and the heat release process of molten salt can be realized. The temperature of molten salt has the greatest influence on the performance of the heat pipe. Moreover,increasing the temperature of molten salt can shorten the start time of heat pipe,increase the working temperature of the working medium in heat pipe and improve the heat transfer power effectively. And the inlet flow and inlet temperature of the cooling water in condensation section also influence the performance of the heat pipe to some extent. The research results provide a theoretical basis for the optimization of single tank energy storage system for molten salt heat release through heat pipe heat exchanger.