Abstract: Hightemperature heat pipes have a good heat transfer performance and can be used for high working temperature. They have an expansive application prospect in the field of thermal protection system of hypersonic vehicle, cooling of space reactor and utilization of solar energy, and so on. The recent progress of hightemperature heat pipes is reported,including the startup characteristic from the frozen state and heat transfer performance of hightemperature heat pipes, the experimental studies, the numerical analysis studies. The effects of the inclination angles, the working fluid parameters, the fill charge ratio, the noncondensable gas, the material, the structure and the sizes on the startup characteristic from the frozen state and heat transfer performance of hightemperature heat pipes are presented.The applications of hightemperature heat pipes for thermal management of hypersonic flight vehicles, cooling of space reactor and utilization of solar energy are summarized. The future development direction is also pointed out, such as the numerical analysis model and engineering application of hightemperature heat pipes. The future research suggestions of hightemperature heat pipes are also put forward.

Key words: hightemperature heat pipes, startup from the frozen state, heat transfer performance, working fluid parameters, thermal protection system；heat pipes