Abstract: The residual water in the surrounding rock of open-pit mines is a key factor affecting the stability of the inner dump slopes. To solve the issue of water treatment in the surrounding rock of the inner dump, this paper took an open-pit mine in the Thar coalfield of Pakistan as the research background and proposed a control scheme for reconstructing a sand layer at the base of the inner dump. The SEEP/W seepage model and SLOPE/W stability model were established using the Geo-Studio software to compare and analyze the variation laws of the seepage field and stability of the inner dump when reconstructing sand layers of different thicknesses and permeability coefficients. The research results show that reconstructing a 11.5 m thick sand layer with a permeability coefficient of 23.8 m3/d or a 5.2 m thick sand layer with a permeability coefficient of 47.6 m3/d can make the slope stability factor meet the safety reserve coefficient requirements. The research results provide a reliable theoretical basis for the optimal design of the water prevention and control scheme for the inner dump in the mine and have important engineering practical significance for ensuring the safe production of the mine.