In order to effectively analyze and determine the development law of the hydraulic fractures and separation of the overlying strata of the 9211 working face, the theoretical analysis and numerical simulation were combined to study the specific conditions of the 3101 working face to establish the overburden hydraulic fracture zone and overlying rock. The simulation model of the separation layer was used to simulate the development of the water-crushing fissure zone and the separation layer. The results showed that the maximum development height of the hydraulic fracture zone of the 9211 working face was about 280 m, which connected with the aquifer. When the working face was fully exploited, there was a large separation zone between the overburden aquifer and the lower rock. The separation space in the hydration area, the exploration and release operation of the overburden aquifer should be strengthened before the recovery mining of 9211 working face.