Abstract: The areas along the mountainous gas pipelines are complicated in geographic and geomorphic conditions, and thus greatly affected by earthquakes. Therefore, the safety and reliability assessment methods of mountainous gas pipelines under the influence of earthquakes were analyzed, which is of important strategic significance to ensure the safety of natural gas supply. From the prospective of the seismic risk and pipeline vulnerability factors, the method of calculating the weight of the index system under group decision-making with the improved Borda method was put forward. Meanwhile, the calculation methods of multi-index comprehensive measurement mentioned in the attribute recognition theory were divided into the types with "or" and "and" logics. Then, the calculation method of multi-index comprehensive measurement with "and" logics was proposed, and the assessment system for the seismic vulnerability of mountainous gas pipelines was established. In addition, the assessment system was applied to a mountainous gas pipeline in western Sichuan, and by introducing the attribute recognition theory, the attribute recognition was performed with the basic data combined with the expert opinions. In this way, the vulnerability level of the pipeline section was obtained. Generally, the results could provide reference for the prediction of the vulnerable pipeline sections in earthquakes and the development of the appropriate measures.