Abstract: In order to study the occurrence mechanism of strata outburst in the process of working face mining, the breakage characteristics of the overburden rock and the occurrence mechanism of strata outburst in the working face were investigated by theoretical analysis, numerical simulation and on-site measurement with the 3# coal working face as the engineering background.Numerical simulation and microseismic monitoring results show that: with the increase of trapezoidal height, the fracture morphology changes from vertical “O-X” type to horizontal “O-X” type; from the narrow face to the wide face, the overhanging width of key layer is larger than its ultimate breaking width, and the breaking of key layer generates high dynamic load; the initial breaking location of the key layer is close to the 3# coal return air roadway, and the combined high dynamic and static load caused by the fault structure induces the strata outburst; and the synergistic control technology of weakening the dynamic load through the directional hydraulic fracturing of the hard roof, and reinforcing the surrounding rock through the support system is put forward.