Abstract: In order to scientifically prevent and deal with the chain effects of natural disasters across time and space, and improve the scientific, targeted, and efficient comprehensive risk prevention of multi-disasters and disaster chains, the authors conducted a classification study on landslide and debris flow disaster chains based on their extensive research experience and analysis of domestic and international case studies. Collapse, landslide, and debris flow disaster chains refer to a series of disasters and chain reactions that are triggered by natural factors or human activities, or both, with the initial disaster being the collapse, landslide, or debris flow of ice, snow, rock, and soil. The subsequent disasters are different combinations of debris flow, surge, torrential flood, dammed lake inundation, and flood impact caused by dam break, and have the basic characteristics of spatial correlation, time continuity, power conversion, and disaster amplification. Based on the authors' experience and comprehensive analysis of many typical cases at home and abroad, a classification system is proposed that consists of the basic understanding, classification basis, and classification system including 5 categories and 21 kinds of disaster chains resulting from landslides and debris flows. The first category is the disaster chains in succession of natural soil or rockfall and landslide, including the intermittent cascade of soil or rockfall and landslide, periodic succession, multilevel straight subduction, and multilevel turning impact. The second category is natural landslide debris flow and its transformation disaster chains, including landslide resulting in surge wave propagation, surge wave-weir-inundation-outburst, transformation into debris flow, and gully blockage-debris flow blockage-flood. The third category is the engineering soil landslide and debris flow and its transformation disaster chains, including landslide-landslide, debris flow-river blocking flood, landslide-debris flow, and tailings dam break-debris flow. The fourth category is avalanche, ice slide, debris flow, and its transformation disaster chains, including avalanche-buried pressure-roadblock-torrent or debris flow, ice slide-rock slide-surge wave-barrier-outburst, and ice slide-glacial lake outburst-torrent or debris flow. The fifth category is disaster chains from landslides and debris flows in volcanic or marine environments, including volcanic landslides-debris flow-locking river, and coastal landslides-tsunami and seabed landslide-debris flow(turbidity current). This study aims to indicate the direction for research on statics, dynamics, and kinematics of every type of landslide, debris flow, and mudslide disaster chain, and lay a theoretical foundation for establishing an engineering technical system and decision support platform for geological disaster chain prevention and response that combines holism and reductionism.