To address the characteristics of a mining area in Jiangxi Province, such as a well‑developed fracturedore zone, significant variations in surrounding rock properties, and the need to protect sensitive surface structures, anumerical model was established using the discrete element software MatDEM. The model simulates the mining andfilling process across 4 levels to study the rules of rock mass deformation and surface subsidence during upwardhorizontal slicing and filling. Surface subsidence data were monitored in residential areas, farmland, and alongroadways.The results indicate that the maximum displacement of the rock mass increases with mining depth across thelevels, while cemented backfills effectively reduce the rate of displacement growth. The values of tilt, curvature, andhorizontal deformation at monitoring points in sensitive surface areas are all below the allowable value for Class I buil‑dings（structures）specified in GB 50771—2012 Code for Design of Nonferrous Metal Mining. This verifies the effec‑tiveness of the ungraded tailings cemented filling scheme.