The mining of coal layers with aquifers in overlying strata has the potential risk of seepage. It is of great significance to effectively predicate the development height of the water conducting fracture zone to prevent the coal seam from permeability during mining. There are 7 coal layers in No. 1 mine of Tashidian mining area in Xinjiang Uygur Autonomous Region. It is urgent to carry out the predication of the development height of transmission fissure zones and evaluate the influence of overlying aquifers on coal layers mining. In this paper, typical finite difference software FLAC3D has been used to simulate and analyze the overlying rock development law of coal seam mining in No. 1 coal mine of Tashidian mining area. The position relationship between the transmission fissure zone and the overlying aquifer has been revealed. It is showed that when the coal layer advancing length is 600m, the bottom of the overlying aquifer will sink to a small degree after coal layer excavation. The height of transmission fissure zone extends to 30~40m above the roof of 81 coal layer, and there is still a distance of 57~67m from the aquifer floor. It is difficult for the transmission fissure zone of coal seam mining to expand to the aquifer. After the excavation of each coal seam, the difference in vertical stress in the position of the aquifer floor is small compared with that before excavation. The research results can effectively guide the coal layer mining activities of No. 1 coal mine in Tashidian mining area.