the evolution of the society and economy has stimulated the development of knowledge service (ks), making it an indispensable solution to address future challenges facing libraries and information institutions. however at present, academic research on knowledge service is falling short and its definition is far from clear and complete. as such, this article proposes the three-dimensional framework knowledge service (tdfks) for libraries and information institutions based on the knowledge value chain model. by making reliability analysis and mean value analysis of a questionnaire survey result, the article clarifies the structure of the three-dimensional framework and verifies the rationality of the tdfks.