<p>This study investigated the environmental hazards arising from overburden rock collapse and surface subsidence due to underground mining through field investigations and discrete element numerical simulations. It systematically examined the dynamic evolution of surface subsidence and elucidated the underlying mechanisms that drive catastrophic progression. The developmental sequence was categorized into four distinct phases: the initial stability phase, the gradual deformation phase, the accelerated subsidence phase, and the terminal stabilization phase. The formation dynamics of surface collapse pits were characterized through four evolutionary stages: the natural stability stage, the initial collapse formation stage, the progressive collapse expansion stage, and the final surface depression stage. A comprehensive analysis revealed that surface subsidence results from multifactorial interactions, where unique geological configurations serve as intrinsic predisposing factors, while mining operations act as primary triggering mechanisms. Specifically, the developmental processes of the eastern, western, and southern sides of collapse pit progressed through three stages: the primary unloading rebound stage, the secondary fracture initiation stage along structural discontinuities, and the tertiary fracture surface collapse stage. In contrast, the development of northern side followed a different three-stage process: the initial unloading rebound stage, the transitional stage from compressive-tensile fracturing to bidirectional tensile failure (including both downward propagation and upward extension), and the slip plane penetration stage. The findings of this study provide a theoretical basis for the prevention and control of surface subsidence pit hazards.</p>