Abstract: Gas distribution pipeline project is an infrastructure construction item in urban construction. Safe operation of gas pipelines is not only related to normal operation of enterprises and daily life of residents, but also taken as an important part of urban safety. A gas distribution pipeline renovation and expansion project in some town is taken as an example to build a leak accident tree of gas distribution pipeline, 7 types of leak accidents of gas distribution pipeline comprehensively are analyzed, the smallest cut set of accident tree including 43 items andget structural importance of basic events causing leak accidents are obtained. Based on the above results, prevention and control measures are proposed to provide references to the safety in construction, audit, operations and management of gas distribution pipeline.