Abstract: Gas overlimit is an important threat to mine safety. Scientific understanding of the fissure development law and overburden permeability distribution characteristics under full mining of coal seams is an important need to realize the selected efficient gas extraction location. Three-dimensional physical similarity simulation experiments were conducted using the E2306 working face of a coal mine in Shanxi Province as the engineering background, and the distributed fiber optic sensing technology and drill hole peeping monitoring method were used to clarify the overburden rock fissure development law under full mining, invert the overburden rock mining fissure network, and combine the fissure dimensionality with the fissure field qualitatively partitioned, and set up the fissure rock fractal-permeability model, which revealed the overburden rock fissure reconstruction under the fractal-permeability characteristics. The fractal-permeability model was established to reveal the fractal permeability characteristics under the remodelling of the overlying rock fractures. The results show that the number of fissures at the boundary of the extraction zone varies parabolically along the strike direction under full mining, and the number of fissures in the middle of the extraction zone varies saddle-shaped along the strike direction. Combined with the fracture dip angle, fracture aspect ratio and fractal dimension, the reconstructed fracture field is qualitatively classified into the following zones: primary rock fracture restriction zone, fracture extension zone, fracture intersection zone, structural fracture compression zone, structural fracture off-layering zone, shear fracture stabilization zone, support fracture transition zone and load-bearing fracture compression zone. The fractal dimension reaches 1.3−1.5 in the strike-breaking fracture extension zone and tendency-supporting fracture transition zone, and the fracture is highly developed. The permeability of overburden rock is related to the distribution of mining fissures, with strike permeability showing “M” type distribution and tendency showing “W” type distribution. The permeability of the fallout zone is 7.4×10⁻⁷−9.2×10⁻⁷ m², and the permeability of the fissure zone is 1.1×10⁻⁹−4.2×10⁻⁷ m²; therefore, the best extraction location is the junction area between the strike-breakage fissure expansion area (0-35 m from the coal pillar) and the tendency-supporting fissure transition area (0-30 m from the roadway), with a height of 50 m from the top plate. The maximum average pure gas extraction rate of a single hole is 1.54 m³/min by using the long strike-length drilling technique.