On the basis of researching the reliability of armored vehicle autoloader, put forward the fuzzy fault analysis method. Analyze the concept basis of fuzzy fault tree analysis. According to the fuzzy calculation rules and fuzzy portal calculation rules, calculate exact value of the event occurrence probability, then ensure that the result more practical. The test shows that the method can resolve the traditional method can not acquire exact value, combine the local test data with engineer experience, which can be widely used in reliability engineering research.