Abstract: Mine debris flow is a typical anthropogenic debris flow formed by the evolution of waste rock and slag generated by large-scale mining of mineral resources, which has the characteristics of frequency, human nature, pollution, controllability, and so on. In order to further explore the influence and control of factors such as bottom bed slope, flushing flow and particle gradation on the start-up process of debris flow and the relationship between the factors, based on the principle of similarity, the scale structure is used to carry out flume Test with the waste rock slag pile produced by mining in Kangshan gold mining area in Luanchuan County, Henan Province. The changes of pore water pressure and water content during the formation of mine debris flow were recorded by sensors, and the phenomenon of slag initiation forming debris flow was observed with high-definition cameras. The test shows that the mine debris flow is mainly started in three ways: top erosion type, fluidization type, and top erosion fluidization type; the critical pore water pressure of the debris flow is negatively correlated with the slope of the bottom bed, and the relationship with the change of fine particle content is not obvious; when the gradation and slope are constant, as the flushing flow continues to increase, the critical water volume of the debris flow at the start of the debris flow shows, and there is a flushing flow rate that is most conducive to slag starting; The flushing flow rate and gradation are certain. The larger the slope, the easier it is for slag to start. The slope and flushing flow are certain, and the fine particle content is 30.36%. Slag is the easiest to start. The research results further enrich the mechanism research of mine debris flow initiation, and can provide reference for early warning, prevention and ecological restoration of mine debris flow.