[Objective] To evaluate the potential chain disaster effects such as debris flows under ultra-standard extreme hydrological conditions, this study aims to establish a comprehensive catastrophe evolution analysis system and propose optimized design solutions to enhance safety control capabilities from the source, transforming the safety control of tailing dams from passive response to proactive defense. [Methods] A combination of numerical simulation and engineering analysis was adopted. Focusing on a typical tailing dam, we constructed an integrated 3D catastrophe evolution analysis model covering the reservoir area and downstream regions. The finite element strength reduction method was used for numerical stability analysis of the tailing dam, accurately identifying potential sliding surfaces and instability failure zones through plastic strain cloud maps. Furthermore, multi-phase flow coupling simulation technology was introduced to combine the process of dam failure and subsequent debris flow progression. Within a digital elevation model, the entire evolution process of post-failure debris flow in downstream valleys was dynamically simulated, quantitatively acquiring critical disaster-causing parameters such as flow velocity, inundation extent, and depth. [Results] (1) Regarding dam stability, under the action of extreme flood levels, the maximum deformation zone identified by the finite element strength reduction method is not located at the dam body but correlates with the reservoir shape and topography. This area represents the most likely initial instability zone, highly susceptible to triggering local or overall landslides, thus inducing dam breaches.(2) Concerning the debris flow evolution process, simulations accurately depicted the descent paths and dynamic evolution characteristics of breached debris flow. Specifically, in terms of flow velocity, maximum flow velocities were observed in the immediate downstream area of the breach, indicating strong erosive capabilities; however, velocities gradually decreased with distance and widening terrain while still posing significant threats to key residential areas and infrastructure. In terms of inundation extent and depth, significant inundation areas formed in downstream valleys, with simulation results clearly delineating risk boundaries corresponding to different flood magnitudes. Maximum inundation depths reached several meters in downstream low-lying areas, directly threatening roads, buildings, and farmlands. Through coupled analysis, the full-chain disaster evolution characteristics from dam breach, debris flow formation to final deposition were identified. [Conclusion] This study proposes optimizing the existing drainage system of tailing dams with a stepped energy dissipation structure which significantly reduces the velocity and kinetic energy of descending floods, effectively controlling overflow erosion on the dam slope, fundamentally weakening the dynamic basis for overtopping destruction. It elevates the safety control system from traditional passive reinforcement and post-disaster rescue to a new phase of proactive intervention in water flow energy, preventing damage before it occurs, thereby markedly enhancing the ability of tailing dams to cope with sudden excessive floods. The research findings provide important theoretical support and technical references for risk assessment, emergency planning, and engineering renovation and expansion of similar tailing dams.