Abstract: Abstract:In view of the coupling law of erosion overburden fracture evolution and gas migration and emission after mining in the working face of composite key strata, taking 12313 fully mechanized caving face in Wangjialing Coal Mine as the engineering background, through studying the erosion overburden activity and fracture evolution after working face advancing, the distribution characteristics of erosion overburden fracture in the working face are obtained, and the numerical model is established to analyze the pressure relief gas migration law. Finally, the research results are applied to the field gas control and effect test of 12313 fully mechanized caving face.The results show that the initial breaking distance of composite key strata in 12313 fully mechanized caving face is 49.84m.The height of the “two zones” composed of the caving zone and the fracture zone of the strike model is 121.1m. The widths of the fracture zone on the side of the cut and the working face are 45.6m and 44.6m, respectively. The caving angles of the cut and the working face are 62° and 60°, respectively.The height of the“two zones” of the caving zone and the fracture zone of the dip model is 115m. The width of the fracture zone on the side of the tape channel and the side of the return air channel is 37m and 40m, respectively. The caving angles of the tape channel and the return air channel are 62° and 63°, respectively.The maximum gas concentration in the upper corner of 12313 fully mechanized caving face can be maintained in a safe range after applying high directional drilling and buried pipe drainage measures.When the buried pipe depth is 17.3 m, the gas concentration in the upper corner reaches 0.478 %, which effectively solves the problem of gas overrun and accumulation in the upper corner, and can provide reference for gas control in coal mining face under similar conditions.