Abstract: The security situation of city gas gate stations decides whether the city gas system in the whole city can get in normal safety operation，so the faulty tree and fuzzy theory method were suggested to analysis safety situation for city gas gate stations. By analysis on the risk factor of city gas gate stations，the faulty tree for the main system of city gas gate stations was established，twenty-eight elementary events causing the main system fault of city gas gate stations were obtained，and safety assessment index system was established. The quantitative analysis on the safety situation of the city gas gate stations was made by fuzzy comprehensive assessment theory and the score of index was determined by expert assessment, and assessment index weight was established by analytic hierarchy process method. The safety degree of the city gas gate stations was obtained by fuzzy theory, and the corresponding key routine safe working was obtained. All these were used in the safety assessment of the city gas gate stations in Changzhou, and the city gas gate stations safety degree is Ⅱ.The example proves that the method used in safety assessment result of the city gas gate stations is effective and reliable，which provide useful reference for safety management on the city gas gate stations.

Key words: City gas gate stations, Faulty tree, Fuzzy comprehensive, Safety assessment

摘要： 城市天然气门站安全状况的好坏，直接影响到整个城市天然气系统的安全运行，为此运用故障树分析法与模糊理论对城市天然气门站的安全状况进行了分析。通过对站内危险因素的分析，建立门站系统的失效故障树，得到引起天然气门站主要系统失效的28个主要事件，建立了门站安全评价指标体系。利用模糊综合评判理论对门站安全状况进行了定量分析，利用专家评分法对指标进行了评分，利用层次分析法计算了各指标层次相对权重；通过模糊理论得出门站安全等级，并给出了相应的日常安全工作重点。用该方法对常州市天然气门站进行安全评价，得出安全等级为Ⅱ级，这与门站实际运行状况相符，说明用该方法对门站进行安全评价是有效、可靠的，能够为城市天然气门站安全管理提供依据。

关键词: 城市天然气门站, 故障树, 模糊综合, 安全评价