Abstract: Aiming at the special engineering scenario where the development orientation of surface valleys in Jincheng Mining Area obliquely intersects with the mining direction of working faces, this study endeavors to reveal the deflection characteristics of surface cracks under the coupling effect of mining-induced stress and topographic conditions, and to clarify the control mechanisms of valley slope gradients and oblique intersection angles on crack morphology and propagation trajectories.Taking 6306 working face of Sihe Coal Mine as the engineering background, a three-dimensional geological model was established through theoretical analysis, field geological mapping, and FLAC 3D numerical simulation.Comparative scenarios with varying oblique intersection angles (30°～90°) and valley slopes (25° and 45°) were designed to systematically analyze the distribution of surface stress fields, deformation evolution, and crack development characteristics during the mining process, with a focus on investigating the influence of valley oblique intersection angles on crack deflection.The findings indicate: ① The surface stress and crack fields in valley regions exhibit asymmetric deflection characteristics. Advanced cracks, primarily tensile in nature, distribute along the valley slope crest lines, developing forward in a “opening-closure (semi-closure)” pattern, with the closure rate positively correlated with the mining advance velocity. ② Steeper valley slopes increase the likelihood of relative displacement and deformation in slope masses, leading to an expansion of shear strain increments and the scope of shear failure. ③ As the oblique intersection angle decreases from 90° to 30°, under the combined action of mining-induced stress and topographically induced additional stress, surface cracks first initiate at valley endpoints. Influenced by the asymmetric stress field deflection effect, their propagation paths gradually undergo regular deflection along the valley axial direction. ④ Smaller oblique intersection angles result in more severe surface damage and more pronounced toe extrusion of valleys: under orthogonal conditions, extrusion forms a “double-peak” uplift, whereas at a 30° oblique intersection, the extrusion zone shifts to the valley bottom center, presenting a “single-peak” uplift morphology.This research provides critical insights for predicting and assessing potential surface cracks during mining operations, offering a scientific foundation for optimizing coal mining schemes and formulating geological hazard prevention strategies in complex topographic settings.