In order to study the influence of coal seam dip angle on water conduction fracture zone of overlying strata, taking the engineering geological conditions of Simingshan Mine as the background, the UDEC software was used to establish the coal seam excavation models under the conditions of 0°, 15°, 30° and 60° coal seam dip angles.
And the influence law of coal seam dip angle on water conduction fracture zone of overlying strata was determined by analyzing the separation layer and plastic failure of overlying strata under different coal seam dip angles. The results showed that the larger dip angle of coal seam, the smaller distance between the most obvious area of separation roof and the boundary of high inclination of goaf. In the inclined strata, the plastic failure zone of overlying strata presented asymmetric characteristics after the coal seam excavation, and the height of the plastic failure zone near the boundary of high inclination of the goaf was significantly greater than that on the other side. Moreover, the larger dip angle of coal seam, the higher the extension height of plastic failure zone of overlying strata；the larger dip angle of coal seam, the smaller distance between the most developed area of water conduction fracture zone and the boundary of high inclination of goaf, and the higher height of water conduction fracture zone.