中文摘要：

通过对近三年37起历史街区火灾进行归纳、统计，利用火灾调查理论知识与事故树相结合，统计分析历史街区火灾中的致灾原因，并利用最小割集和最小径集，根据基本事件发生概率，计算出顶上事件的发生概率．最后，对事故树进行重要度分析，确定基本事件的重要顺序，并针对历史街区火灾致灾因素提出控制对策，降低顶上事件发生的概率．

英文摘要：

based on the induction and statistics of 37 in the last three years from the historic district fire, the authors integrated the theoretical knowledge of fire investigation with the fault tree, analyzed the fire hazard reasons in the historic district, meanwhile, the paper utilized minimal cut sets and minimal path sets, calculated the probability of occurrence of the top event according to the probability of occurrence of the basic event. Finally, important analysis of the fault tree was carried out to determine the order of basic events, and the control policy was provided, based on causal factors of the historic district fire, so as to reduce the probability of occurrence of the top event.