Abstract: Taking a debris flow disaster at a waste dump of an open-pit mine in Liaoning Province as a case study, this paper analyzes its fundamental characteristics, formation conditions, and disaster evolution process, and reveals its disaster-causing mechanisms. The results show that this debris flow belongs to a slope-erosion type induced by rainstorms. The steep valley slope and the loose accumulation of materials from the upstream waste dump easily generate internal slope seepage flow under heavy rainfall, triggering shallow landslide. The high and steep topography provides sufficient potential energy for the landslide mass to transform into a debris flow. Meanwhile, the Quaternary fluvio-alluvial deposits within the channel provide the material basis for the incision and erosion of the debris flow. Combined with the abundant water supply from sustained heavy precipitation, a large-scale debris flow is ultimately triggered. Based on the topography of the waste dump and the characteristics of the disaster, a comprehensive control scheme that integrates water interception-drainage measures with multi-level retaining and energy dissipation is proposed. The control effect is significant after scheme implementation, effectively mitigating the risk of debris flow disasters. This study provides practical reference and theoretical support for the cause analysis and prevention-control design of similar mine waste dump debris flows.