Abstract: In deep coal mining, geological conditions and in-situ stress environments are highly complex. When hydraulic fracturing technology is applied to destress composite hard roofs, the fracturing effectiveness is jointly influenced by multiple factors, including the lithology of overlying and underlying strata, borehole placement horizon, and borehole angle, while the mechanisms of fracture propagation and evolution remain insufficiently understood. To investigate fracture trajectory patterns under different stratigraphic conditions and borehole inclinations, this study takes the 72313 working face of the Xutuan Coal Mine as the research background. The mechanical properties of roof rocks and the pore structure characteristics of the overlying strata were analyzed. Combined with XSite numerical simulation software, the effects of different fracturing horizons and borehole inclinations on hydraulic fracturing performance were examined. Based on synthetic rock mass technology and the distinct lattice method, a coupled model of particle motion in the rock matrix and fluid flow was established.The results show that: Under high confining pressure, fine sandstone exhibits significant microcrack closure, a marked increase in elastic modulus, and a high brittleness response, whereas mudstone, due to its loose structure, high clay content, and strong pore sealing, shows pronounced plastic deformation capacity. Multi-source scanning results reveal that fine sandstone possesses good pore connectivity and a stable seepage network, facilitating fracturing fluid transport and fracture activation; in contrast, mudstone has isolated pores and low permeability, which tend to form high-pressure gradients and induce fluid instability, thereby suppressing fracture volume growth and network complexity. Numerical simulations demonstrate that borehole deviation angle can alter the local stress perturbation structure, inducing directional deflection of fractures; when the deviation angle is 60°, fracture paths align more closely with the principal stress direction, and the branching network develops more fully. Sensitivity analysis indicates that tensile strength, fracture toughness, and compressive strength are the primary sensitive parameters, together contributing more than 70% to fracture network volume, while elastic modulus, Poisson’s ratio, and porosity play relatively minor roles. Field observations further show that prioritizing fracturing slotting in fine sandstone horizons can promote fractures with greater connectivity and extension capacity.The findings provide theoretical support for optimizing hydraulic perforation layout and fracturing effectiveness in deep mining environments, thereby improving fracturing efficiency while ensuring roadway safety.