Intelligent information service is a form of interaction between information service and  big data. An Effective analysis of volume, variety, velocity and valuable but low density big data is the key to promote the researches and development of intelligent information service. Based on nearly five years (2013-2018) relevant articles which were published in Web of Science by librarians, the big data analysis methods and the research topics of intelligent information service were analyzed. Through literature study and frequency analysis,  a layered analysis  framework was constructed, which includes big data analysis layer and application layer.