Abstract: The heat pipe cooled reactor adopts the solid-state reactor design concept and passively transfer the heat out of the core through heat pipes. This paper summarizes the development history of the heat pipe cooled reactor, from the conceptual initiation, the active exploration and to the breakthrough. The technical characteristics of heat pipe cooled reactors are analyzed, including the key advantages, such as solid properties, inherent safety, simple operation, easy modularization and expansion, and transportability. In addition, this paper summarizes the technical status of heat pipe performance, material technology and energy conversion in heat pipe cooled reactors. The challenges in the further development of heat pipe cooled reactors are put forward, such as material technique, manufacturing, and operation maintainability. The future development trend of heat pipe cooled reactors is clarified, which provides a direction for the development and application of the innovative heat pipe cooled reactor technology. Overall, the heat pipe cooled reactor has broad application prospects in deep space exploration and propulsion, land-based nuclear power supply, sea exploration and other scenarios,  which may become one of the most creative technologies to change the future nuclear power patterns.