Abstract:There are abundant moraine soil sources distributed in the Qinghai–Tibet Plateau of China, with complex historical causes, changeable material structure, and large differences in mechanical properties. Moraine landslide often occurs under the action of rainfall and ice and snow melting. The debris of landslide enters the gully and mixes with water flow, which is very easy to produce the moraine landslide—debris flow—dammed lake disaster chain, which is the key and difficult point of disaster prevention and reduction in the plateau. In recent years, the Sichuan—Tibet railway project and major hydropower development in Tibet have faced a great threat from the moraine landslide—debris flow—dammed lake disaster chain. It is a major national demand to improve the capacity of disaster prevention, reduction and relief. Moraine landslide—debris flow—dammed lake—dam-breaking flood is a chain disaster process of cascade amplification, which involves complex dynamic evolution mechanisms such as landslide initiation, movement behavior transformation, erosion amplification along the process, multi-stage river blocking superposition, and dam break water–sediment coupling. Especially under complex meteorological conditions, there are some problems such as unclear mechanism, inaccurate model, and lack of simulation technology. It is urgent to carry out the research on the complex dynamic mechanism, control theoretical model, and whole process numerical simulation of moraine landslide—debris flow—dammed lake disaster chain process. Combined with the research status at home and abroad, five research contents are further proposed: 1) Evolution of mechanical properties of moraine soil under complex meteorological conditions. 2) Dynamic disaster process and migration model of moraine landslide—debris flow. 3) Formation mechanism and simulation of moraine landslide—debris flow—dammed lake. 4) Mechanism of erosion and outburst of moraine dam and the process of flow channel expansion. 5) Mechanism of water-sediment interaction in the downstream channel and the simulation of flood evolution. Many preliminary explorations and research work have been carried out to preliminarily reveal the migration of moraine landslide debris flow and multi-stage river blocking mechanism, a dam break evolution model that can consider water erosion and intermittent collapse of the broken slope has been built, and the simulation method of moraine landslide—debris flow—dammed lake disaster chain evolution process has been discussed. The results lay a foundation for further understanding of the complex dynamic mechanism of the moraine landslide—debris flow—dammed lake disaster chain process, constructing the control theoretical model and developing the whole process numerical simulation system. And the results are expected to provide a theoretical basis for the mechanism of moraine landslide—debris flow—dammed lake disaster chain and technical support for non-engineering risk reduction and emergency disposal decision-making.