Abstract: Underground mining induces the movement, deformation and failure of bedding rock slope in mountainous areas, which develops into geological disasters such as landslides and collapses. In this paper, based on UDEC discrete element method, this paper studies the influence of repeated mining of underground coal seam on the location of bedding rock slope. The results showed that: the subsidence affected by mining decreases with the decrease of buried depth, and the deformation of strata after mining is discontinuous. Compared with single-layer mining, repeated mining will lead to a significant increase in the horizontal deformation of slope. Repeated mining leads to the development of new fractures and fracture groups in the slope, which is more likely to lead to the destruction of the weak structural layer and further reduce the stability of the slope. The dynamic development process of “deformation accumulation-generation-expansion-closure” during single-layer mining will evolve into a dynamic development process of “deformation accumulation-development and expansion-development and stability” during repeated mining.