In underground engineering, roadways often intersect faults containing weak interlayers and fractured zones with varying dip angles. Under such geological conditions, the surrounding rock exhibits pronounced variability in geometry, reduced mechanical strength, and irregular failure patterns, which significantly complicate roadway construction and support design. The heterogeneous structure and mechanical heterogeneity of the rock mass lead to non-uniform deformation and localized instability around the roadway. Consequently, understanding the influence of fault geometry and mechanical weakness is essential for evaluating stability and developing effective support strategies in complex underground environments.In underground engineering, roadways frequently intersect faults containing weak interlayers and fractured zones with varying dip angles. Under such complex geological conditions, the surrounding rock exhibits heterogeneous geometry, low mechanical strength, and non-uniform failure patterns, which pose significant challenges for roadway construction and support design. This study investigates the deformation behavior of roadway surrounding rock in relation to fault dip angles and fault–roadway intersection geometries. A numerical model is developed using measured mechanical parameters from an iron mine in Yunnan Province to assess the stability of the roof, sidewalls, floor heave, and fault–roadway intersect[1]ions under unsupported conditions. The results provide insights into deformation localization and critical regions requiring reinforcement, offering guidance for safe and efficient underground excavation in structurally complex environments.“Numerical simulations demonstrate that the displacement of the roadway surrounding rock correlates positively with the fault intersection angle, transitioning to a linear increase when the angle surpasses 120°.Concurrently, the rock mass becomes highly susceptible to widespread shear failure, accompanied by a progressive enlargement of the plastic zone as the angle grows.”For roadways intersecting two faults with different dip angles, surrounding rock displacement at each monitoring point decreases with increasing fault dip angle. The dip angle of 45° is identified as the most unfavorable condition. Displacement at fault?roadway intersections is consistently larger than that of roadway sidewalls; sidewall displacement is roughly equivalent to roof subsidence, and both are greater than floor heave. Additionally, the volume of the plastic zone declines as the dip angle rises. Numerical simulations were further carried out toevaluate the overall roadway stability under special dip angles, horizontal inter layers (0°), and varied spatial relationships between roadways and faults. The stability ranking is as follows: roadways located above two faults exhibit the best stability, followed by roadways situated between two faults, whereas roadways cutting through a single fault present the worst stability performance.