With the enrollment expansion in colleges and universities in China, the number of school students increasing, more and more college students' dormitory building also.Due to the improvement of living conditions, school supplies and living things growing.The hidden danger of fire accidents will increase gradually, once fire accident happened, will directly damage the national and personal property, and life safety threat to students, seriously affect the normal teaching and living order of the school. The fire accident causes are diverse, through the fault tree qualitative and quantitative analysis the influence of various factors on the students' dormitory fire accident size,?to develop students' dormitory fire accident preventive measures has certain guiding significance.This paper takes a College dormitory 5 as an example, using fault tree analysis of the causes and consequences of the dormitory fire accident,and corresponding preventive measures are put forward.Analysis results show that the fire alarm delay, delay the time, found that don't timely, inadequate fire, fire control facilities of the failure is the most pressing problems,While other problems need to improve in peacetime work somewhat can be well improved.In addition, the corresponding fire prevention measures, the probability of fire accidents will be greatly reduced.