Research conclusions: (1)The deep hole grouting along with large pipe roof construction method is feasible for dealing with geological disaster of fragmentary flows(slack )，which can compact and cement the rock to enhance the mechanic property and at the same time , the large pipe roof can form a bearing anchor along with rock. ( 2 ) The more attention should be paid to the sketch for the geological disaster area. ( 3 ) The more attention should be paid to the details of the construction techniques; The excavation length is not allowed to exceed the design length, the grouting-stopping wall on bottom should be designed of stepped gear type and the wall seam should be closured with concrete. ( 4 ) The more attention should be paid to drainage in disaster area. For draining the water, the methods of drainage and blocking can be used.