Abstract: Underground coal fires have a serious impact on coal resources and the environment, and the accurate detection of the location of fire areas is the premise and key to carrying out coal fire control. Based on the formation process of coal fire, this paper combines literature review, numerical analysis, physical experiments, field investigation and other methods to study the underground coal fire detection technologyies and their engineering applications. Firstly, the principles and characteristics of different existing coal fire detection technologies are introduced in detail, and their advantages and disadvantages are analyzed and summarized. Then, combined with actual cases, the research and engineering application status of various detection technologies are expounded, and the problems existing in underground coal fire detection at this stage are revealed. On this basis, the research focus and development direction of coal fire detection in the future are proposed. The research results can provide important technical support for the scientific research and prevention of underground coal fires in China.