Abstract: In response to the serious air leakage problem in the goaf caused by the overlapping mining of dual series coal seams in the 8105 fully mechanized mining face of Guandi Mine, a combination of numerical simulation and on-site monitoring was used to study the laws of overlying rock fracture and dynamic evolution characteristics of fractures, revealing the connectivity mechanism of multi-layer goaf and the distribution law of coal spontaneous combustion danger zones. The results show that the overlying strata in the goaf of Jurassic coal seams exhibit a composite form of roof collapse, floor bulging, and shear failure around the coal pillars; The mining of coal seams in the Carboniferous system sequentially triggers the rupture of the basic roof, lower key layers, and upper key layers. The rupture of the upper key layer ultimately penetrates the dual system goaf, forming the main air leakage channel, and the rupture of the lower key layer exhibits a periodic characteristic of about 60 meters. The air leakage paths within the critical interlayer fracture zone can be divided into two categories: dynamically developed fractures and stable edge fractures. The significant impact of air leakage conditions on the distribution of spontaneous combustion hazard zones: when there is external air leakage, the hazard zone is concentrated within the range of 100-175m behind the working face and significantly expands on the inlet and outlet air ducts; After cutting off the air leakage, the dangerous area was reduced by about 60% and moved about 30 meters towards the working face.