The work aims to analyze the service encounter in community group-buying service by applying the service encounter theory involved, so as to capture user requirements accurately, improve user experience and propose a design scheme for service system improvements. First of all, the service encounter between various elements in community group-buying was analyzed. The service contact points were obtained by analyzing user behaviors. The user satisfaction of service contact points was evaluated through questionnaire survey and the service gaps, namely, service contact points with low evaluation value, were screened out. In this way, user requirements were explored, and the effective mapping relationships between user requirements and system functions were established to obtain functional indicators of community group-buying service systems. Then, by establishing a structural equation model (SEM) on community group-buying satisfaction, the influence weight size of each functional indicator on user satisfaction was determined to guide the design of the community group buying-service system. It completes the construction of the community group-buying service system and the innovative design of its related supporting facilities. The theoretical approach and the practical path can help to obtain the diversified needs of users, and grasp the focus of community group buying service, providing theoretical and practical reference for other similar service design.