【英文摘要】Based on remote sensing interpretation, field investigation, mapping, and model experiments, forming mechanism of debris flow induced by break of glacier lake. The results provide parameters and scientific foundation for hazard mitigation in construction of highway, hydropower, water conversancy, and city and town. The study also improves the theory of glacier-lake debris flow. The work includes (1) inventory of 461 glaciers and 131 glacial lakes, and there are 67 debris flow valleys having glaciers; 7 glacial lakes have potential of break and risk assessment is made. An inquiry system is made for glaciers and glacial lakes in the Ranwu-Peilong section of the Sichuan-Tibet Highway; a danger division map of 1: 100 000 is also created; (2) a systemic research is made for the processes of lake break, debris flow formation, debris damming, dam break, and dam-break flood. 35 experiments have been conducted and critical conditions are gain for lake break and debris flow forming. Calculation formulas are built for the maximal surface velocity, peak discharge, volumetric concentration, sediment delivery, debris transport, and damming coefficient of debris flow, as well as the flood discharge by break of debris dam. Breakthrough has been made in fundamental theory; (3) a warning system is made for debris flow by glacial-lake break; prevention techniques are proposed for the dam-break debris flow, which improves the level of hazard mitigation.