Abstract:In response to the complex factors such as residual coal pillar pressure and goaf water accumulation in the overlying 4-coal goaf during the initial mining period of Guojiawan Coal Mine in Guoneng Yulin Company, the pressure step distance and stress distribution of the 51208 fully mechanized mining face were studied through theoretical calculations, FLAC3D numerical simulation, and other methods; By adopting engineering methods such as geophysical exploration and drilling in advance, identify and release accumulated water in the overlying goaf that affects safety production; Finally, through the safety mining practice of the 51208 fully mechanized mining face and the summary of the mining pressure laws such as the initial mining and periodic pressure of the 51208 fully mechanized mining face, it was found that the initial pressure and periodic pressure step distances of the 51208 fully mechanized mining face were 70m and 10m, respectively. This effectively verified the necessity of theoretical calculation, numerical simulation, advance geophysical exploration, drilling and other engineering methods, as well as the rationality of safety technical measures. The main hidden disaster causing factors affecting the pre mining pressure of the 51208 fully mechanized mining face, goaf water accumulation, coal seam outcrop and gap development were successfully controlled; We have accumulated valuable experience that can be learned from for the next step of safe mining of similar fully mechanized mining areas, which has certain promotional significance for the region.