Abstract: In order to ensure the safe and efficient mining of fully mechanized coal mining face with steeply dipping coal seam and large mining height under the coal gangue interbedded roof, the frequent roof caving disaster in working face is one of the key problems to be solved urgently. The research method of physical similarity simulation experiment and theoretical analysis is used to analyze the stress distribution, evolution rule, failure and leakage characteristics of the coal gangue interbedded roof in the face with steeply dipping coal seam and large mining height.The results show that the roof of the coal gangue interbedded is compressed and fractured above the top beam of the support. During the moving support process, the separation layer and the step sink. The support resistance of the support increases sharply. The fractured coal gangue layer is squeezed and broken due to the repeated support of the support. The support stress is transmitted to the coal body in front of the work. The support resistance decreases gradually, and the support pressure in front of the work face overlaps and increases.the stress concentration causes the roof of the coal gangue interbedded to break in advance and rib spalling. The broken coal rock mass leaks from the front of the support along the coal wall.Through theoretical calculation, the maximum subsidence of the roof before the leakage of the coal gangue interbedded is 1340mm, and the simulation experiment result is 1500mm. The specific measures are: moving the frame with pressure, improving the initial support force of the support, and improving the stability of the coal wall.