Abstract: For the problem that it is easy to appear wall caving and roof fall during fully mechanized caving face passing through geological fracture zone, combined with the actual geological conditions of a mine, the mechanical model and the structural mechanics analysis model of the beam of the end roof are constructed based on the roof characteristics, and the formula for calculating the maximum caving height and grouting reinforcement thickness h is obtained. Through the numerical simulation of UDEC, when the geological fracture zone is developed to the coal seam, simply consider to reinforce roof can not effectively control the stability of the terminal roof. The strength of the coal wall can be increased by grouting through the coal wall. The strength of the coal wall grouting should not be less than 1.5 MPa, and the thickness of the grouting reinforcement should not be less than 2 m.