Moraine supplied-rainstorm debris flow is a unique geographical process that often can be seen in high elevation glacial margin area,the potential harm from the debr is flow has not be recognized enough because of its invisibility,and only a few researchers pay at tention to it.Based on the debris flow mechanism progress and the field survey,this article took Moxi Basin as an example,where distributed many moraine supplied-rain storm debris flow,and analyzed the forming factors and process,and presented the 4 steps of this debris flow process:branch water converging stepy individual particle material starting up stepy unde-rerosion and lateral erosion stepy debris flow initiationstep.F inally,this article summarized related problems about the mechanism of moraine supplied)rainstorm debris flow which need to be further studied.