During the manufacturing and service processes, high-temperature conditions are likely to lead to product performance degradation and life loss. Surface coating protection technology is one of the ideal ways to prevent the failure of high temperature performance of products. Diamond-like carbon (DLC) coating has a wide application prospect due to its excellent comprehensive properties, such as high hardness, excellent wear resistance and corrosion resistance, low friction, self-lubrication and good thermal stability. However, with the rapid development of photoelectric information field, the manufacturing and service environment of products is becoming increasingly complex and extreme, especially under high temperature conditions, which puts forward more stringent requirements for the protective performance of DLC coatings. The lack of thermal stability limits the application of DLC coatings under harsh high temperature conditions. In this paper, the research and development on thermal stability of DLC coatings were reviewed. Firstly, the advantages and disadvantages of various heat treatments combined with ex-situ testing, thermal analysis, high temperature in-situ test and simulation calculation were comparatively addressed. Heat treatments combined with ex-situ testing could not determine the fine change of composition structure of materials during heat treatment. Thermal analysis was mainly used to determine the transition temperature of coating structure, which could only indirectly reflect the evolution law of coating structure at high temperature. High temperature in-situ testing effectively overcame the shortcomings of the above research methods, and could observe the evolution process of morphology, structure and properties of coating materials in real time, dynamically and continuously during high-temperature treatment, which was the most ideal research way to reveal the changes of thermodynamic properties of coatings. Simulation calculation could break through the limitations of existing experimental characterization methods, efficiently and conveniently simulate the thermodynamic behavior of DLC coatings at high temperature from molecular and atomic scales, and at the same time promote and guide experimental research. Secondly, the influence process and mechanism of composition, preparation method and annealing environment on the thermal stability of DLC coatings were summarized, and it was found that the hydrogen-free DLC coatings with high sp3 content presented the best thermal stability. However, DLC coatings with different thermal stability could be obtained by different preparation methods by influencing the coating structure, sp3 content and hydrogen content. Moreover, the deposition temperature, substrate bias, deposition pressure and other preparation processes would also affect the thermal stability of the coating. In addition, the thermal stability of the coating in vacuum and inert gas environments was better than that in oxygen environments. It was revealed that adding third elements into amorphous carbon matrix and introducing multilayer structure and gradient structure in DLC matrix could significantly enhance the thermal stability of DLC coatings. Among them, element doping could regulate the thermal stability of the coating by changing the composition and bond structure of DLC. The multilayer and gradient layer structure design mainly improved the thermal stability of the coating by reducing the stress of the coating and breaking through the key preparation of thick films. Combined with the evolution law of coating microstructure, the failure mechanism of DLC coatings at high temperature was further expounded from the graphitization, oxidation, dehydrogenation of the coating itself and peeling behavior. Finally, the common challenges and future trends of designing and developing DLC high temperature protective coating materials were analyzed and prospected.