Abstract: When the coal mine is mined out from the mining area, the overlying strata of the goaf will be deformed and damaged.On the one hand, the coal resources will migrate to the fracture developed parts.On the other hand, there are some hidden dangers in the mining area.In order to ensure the safety of coal mining engineering, and accurately grasp the distribution of mineral migration, this study adopts the key layer theory and numerical simulation method to analyze the fracture evolution law of mining overburden.The results show that the fracture presents the "trapezoidal platform" development characteristics in the strike and tendency, and the fractures above the goaf present an "O" ring distribution with compaction in the middle and developed around; the pressure relief area is formed at the edge of the goaf, and the fracture is developed in this area, which has good pumping effect.In addition, the width of the compaction area in the central part of the goaf is 175 m, the fractures are not developed, and the separation rate tends to zero; the separation rate is larger within the range of 35 m at the side of air inlet roadway and 30 m at the side of return air roadway, and the maximum separation rate reaches 136 mm/m.This study obtains the law of fracture evolution of mining overburden in Pingdingshan No.13 coal mine through numerical simulation, which not only provides a theoretical basis for coal mine resource extraction, but also provides a guarantee for coal mine safety accident prevention and control.