Karst-fissure aquifers within the Carboniferous-Permian carbonate sequence are typically thick and high-pressure. Concealed structures, especially faults and collapse columns, are widely developed, and some exhibit strong vertical hydraulic connectivity, making coal-floor water-inrush accidents likely under mining disturbance. Centering on the lower group of the Zhuozishan Coalfield, this study integrates data compilation and statistical analysis, hydrogeological characterization, numerical simulation, and theoretical calculations to delineate karst-fracture development and aquifer behavior, simulate water inrush along faults and collapse columns, and evaluate the feasibility of safe extraction in the lower coal group. The results show that: The karst development of Ordovician limestone in Zhuozishan coalfield is obviously affected by lithology, geological structure, topography and distribution of hydrological network, mainly in the Zhuozishan formation limestone with a thickness of less than 100 m, especially in the upper 50 m fractures and small karst are more common. The heterogeneity of the Ordovician aquifer in Zhuozishan Formation is characterized by the uneven water richness in the plane and the uneven vertical discharge interval, and the water level of the Ordovician aquifer is generally decreasing. In order to prevent water inrush of F61 fault and collapse column during mining of 16# coal seam in Luotuoshan coal mine, the width of fault waterproof coal column should be not less than 60 m and 125 m respectively. The water inrush coefficient of Ordovician limestone water on the floor of most areas of 16# coal seam is greater than 0.06 MPa/m, which belongs to the dangerous area of mining with pressure.