In the sedimentary strata, rock strata exhibit layered feature and have an obvious level. Overlying rock often produces separation layer along the level after the underground excavation. However, due to the difference of each layer, but the rule of separated layer is extremely complex due to the difference of each layer, the change of the mining process and the height difference in the level and other factors. However, the disturbed overburden separation is an important basis for studying the subsidence of the surface and implementing the damage control. Therefore, in this paper, the phenomenon, feature and regularity of disturbed overburden separation are found by means of numerical simulation. The paper reveals the mechanical mechanism of the development of overburden separation, and it is also explores the way and method of disturbed overburden separation, and verified by experiment. It is of great importance to understand the law of surface subsidence through the overburden separation development process