Underground coal mining induces significant surface deformation and environmental damage, particularly in deeply buried mining areas with thin bedrock and thick alluvial layers. Based on the case study of the Zhaogu No.2 coal mine in Xinxiang City, Henan Province, China, this study employs a comprehensive research methodology, integrating field investigations, numerical simulations, and theoretical analyses, to explore the surface subsidence features at deeply buried mining areas with thin bedrock and thick alluvial layers, to reveal the effect of alluvial thickness on the surface subsidence characteristics. The findings indicate that the surface subsidence areas span 4.2 km2 with an advanced influence distance of 540 m. The rate of surface subsidence primarily depends on the panel's position and its advancing rate. Moreover, the thickness of the alluvial layer amplifies both the extent and magnitude of surface deformation. The displacement of overlying rock primarily exhibits a two-stage progression: the thin bedrock control stage and the alluvial control stage. In the thin bedrock control stage, surface subsidence initiates with relatively low subsidence values and amplitudes. Subsequently, in the alluvial control stage, surface subsidence accelerates, leading to a rapid increase in both subsidence values and amplitudes. These characteristics of rock formation displacement result in distinct phases of surface subsidence. Furthermore, the paper addresses the utilization of surface subsidence areas and proposes a method for calculating reservoir storage capacity in these areas. According to calculations, the storage capacity amounts to 1.05e7 m3. The research findings provide valuable insights into the surface subsidence laws in regions with similar geological conditions and practical implications for the management and utilization of subsided areas.