As the key technology of intelligent coal mining, gangue recognition technology has become a technical challenge in the field of intelligent coal mining. This paper firstly introduces the importance of coal gangue recognition technology and its impact on production safety and economic benefits. Subsequently, it points out such existing problems and challenges as the difficulty of identifying coal lumps and rock seams with different shapes, colors and depths, and the influence of noise as well as complex background in the process of identification, etc. In the next section, it describes in detail the key problems of coal gangue identification technology for integrated face mining. Next, the main methods of coal gangue recognition technology in comprehensive discharge working face are elaborated in detail: ray method, visual method, and vibration and sound signal method. By analyzing the principle, technical characteristics, advantages and disadvantages of gangue recognition methods, the current application status of gangue recognition technology in the comprehensive discharge working face, as well as the applicable conditions and problems of various methods are comprehensively evaluated. Finally, this paper discusses the future trend of this technology by emphasizing multi-sensor fusion, deep learning, intelligent decision-making and real-time monitoring as the core of current technological development.