Abstract: In order to accurately grasp the evolution laws and distribution characteristics of the overburden cracks in the mining of a single coal seam and coal seam group, physical similar simulation experiments, on-site drilling exploration, theoretical calculations and other methods are used to analyze the characteristics of overburden migration and fracture and the characteristics of mining cracks during coal mining. The research results show that under repeated mining conditions, stratified cracks and longitudinal cracks appear in overlying rocks accompanied by advanced cracks. In forming a structure of “goaf-workface” and “goaf-goaf-workface”, the overburden fissures experienced six dynamic cyclical stages of generation, expansion, closure, re-generation, penetration, and re-closure. The coal seams group forms a “trapezoidal” fissure area during a mining. Under secondary and multiple mining operations, the overburden is affected by the overlying load. The influence of the “cantilever beam” formed by the coal pillars at the boundary of the coal seam and the mining of the lower coal seam makes the fissures on both sides of the working face significantly higher than the middle of the working face, and the overlying rock forms an “M”-shaped fissure distribution pattern. The overburden rock is periodically broken under the influence of mining, and deformation, migration and fracture collapse occur simultaneously in single or multi-rock strata. It can be seen that there is a hard rock layer that controls the upper rock layer and its control rock layer moves and breaks simultaneously in the form of composite beams. According to the fracture characteristics of the overburden rock, a composite rock beam mechanical model based on the failure characteristics of the repeated mining of the Winkler elastic foundation coal seam group is established. The evolution height of the overburden rock fissures calculated from the model is similar to the height measured in the similar simulation experiment and the site, which shows that this model can be used as a basis for calculating the evolution height of overburden cracks in the shallow coal seams group that are repeatedly mined.