In the academic libraries' efforts to support digital humanities and social science, GIS service plays an important role. However, there is no general service model existing about how libraries can develop GIS services to best engage with digital humanities and social science. In this study, we adopted the action research method to develop and improve our service model. Our results suggested that a library's GIS service can support humanities and social science from the research collaboration, learning support, and outreach perspectives, with different focuses according to the stages of learning and research. The research framework adopted in this study not only can serve as an efficient tool for developing GIS services but also can be expanded to other library service areas.