Abstract: Mine water inrush and collapse accidents are among the most destructive geological disasters, where the movement and deposition behavior of solid–fluid two-phase flows directly determine the scale of disaster evolution and the difficulty of mitigation. In mine water inrush and collapse accidents, accurate prediction of the flow and accumulation characteristics of crushed stone under different geological conditions is crucial for disaster management. The transport and deposition of crushed stone during such incidents complicate the disaster scenario. Through physical modeling and CFD-DEM coupled numerical simulations, this research systematically investigates the transport and accumulation characteristics of debris in mine water inrush and collapse accidents under varying water pressures and roadway inclination angles. Utilizing a combined approach of physical modeling and fluid-solid coupling simulation, this research replicated the full dynamic process of debris flow and unraveled the underlying macro-meso scale mechanical mechanisms of the collapsed mass. The results reveal that the crushed stone transport and accumulation process can be divided into three distinct stages: initial deposition, rapid spreading, and stable accumulation, with the deposit sequence remaining consistent with the initial accumulation sequence. As the water pressure increases, the crushed stones form an "M"-shaped double-peak accumulation below the water inrush opening, while a steeper roadway inclination leads to longer spreading distances, more concentrated deposition, more prominent transverse ridges, and greater accumulation heights. On a macroscopic scale, the particle size exhibits significant sorting characteristics, with large particles accumulating at the front and periphery of the deposit, while small particles are distributed at the back and bottom of the deposit. In the meso-scale analysis of contact characteristics, the coordination number contour exhibits a pattern of being low at the edges and high at the center. Moreover, its peak value follows a consistent non-monotonic trend, initially increasing and then decreasing with the increase of water pressure and inclination angle. This study investigates the transport and accumulation characteristics of crushed stone under the influence of multiple factors and offers key data and theoretical guidance for optimizing the design of rapid rescue pathways construction and for assessing construction safety risks in mine water inrush and collapse incidents.