Due to the low top coal caving rate and the difficulty in field measurement of mixed flow law of coal and gangue, this paper takes No.45 coal seam +575 horizontal working face in the north mining area of Wudong Coal Mine as the engineering background, adopts similar simulation test and numerical simulation analysis method, and studies different coal caving methods and technological parameters in steep high caving mining. Firstly, adopts similar simulation test method, The different caving methods and technological parameters of steeply inclined large section and high fully mechanized top coal caving mining are studied, and the accuracy of theoretical analysis is verified. At the same time, the movement law of loose top coal is obtained, that is, the movement track is approximately straight line, and the closer it is to the coal caving port and the central axis, the faster the particle flow rate is. Secondly, the numerical simulation method is used to count the mixed flow law of coal and gangue under different coal caving methods and process parameters, so as to guide the design and optimization of coal caving technology in working face. Finally, the boundary between coal and gangue and the ellipsoid formed in the process of coal caving are inversed, and compared with the theoretical analysis results, which verifies the rationality of the theoretical analysis, and provides a theoretical basis for clarifying the mixed flow law of coal and gangue in steep section and high fully mechanized caving.