The H Index proposed by American physicist George Hirsch is a new thought and method used to evaluate the research results of scientific researchers, which has been paid attention to and applied in the field of knowledge and academia since its inception. This theory has formed rich research literature in the fields of individual academic evaluation and academic periodical evaluation. Through the analysis of the application of H index to library practice, it can be found that there is great development space for the application and academic research of library based on H index. The Library resource purchasing and information service based on H index is the two extension directions of the future H Index application in library service, but it is necessary to pay attention to the comprehensive application and dynamic monitoring of various evaluation indexes in the application process.