The digital library has to retrieve in the mass information what the users need to provide users with more and higher quality resources. In this paper the author analyzes the information resources and hierarchical query model of the digital library platform, introduces grid technology, explains the specific advantages and service connotation of the digital library, and analyzes the degree of realizing the hierarchical service of the digital library to meet the actual needs of users. In view of the problems of low data processing ability, lack of resources and content, and lack of interaction in the digital library, this paper puts forward a series of strategies to optimize the service ability of the digital library's hierarchical retrieval platform, so as to provide users with accurate and all-round personalized information that can meet their query semantics and provide users with satisfactory services.