The continuous expansion of urban population and space scale, the continuous increase of daily average traffic trips and per capita travel distance, and the increasingly frequent urban economic activities have formed diversified travel demands. Based on the survey data, this study combs the commuter travel mode chain of Xi'an with public transport as the main body, and explores the satisfaction of current commuter bus passengers. First of all, the impact factors of each link of the public transport travel mode chain are sorted out. Based on the three levels of reachability, accessibility and connectivity, this paper proposes an evaluation index system of urban public transport commuting service, including convenience, safety, comfort, reliability and other specific indicators. Secondly, the commuting satisfaction evaluation scale is constructed to evaluate the subjective experience of travellers in the travel process. The results show that there is a gap between the expectation of commuters and the perception of public transport service attributes. Among them, "convenience" and "comfort" of public transport are the most important service quality attributes related to the satisfaction of commuters, and residents are the least satisfied with the convenience of transit, and public transport lines fail to meet the commuting needs of some residents. When transport operators provide services that meet passengers' expectations, passenger satisfaction and PBT utilization rate will be improved, service quality of public transport mode chain will be improved, sustainable transport will be promoted, and energy consumption and emissions will be reduced.