1, the traditional consulting mode: consultants sit at the consulting desk and handle all kinds of consulting, from simple questions to research-oriented work with a certain depth. 2. Teaching-oriented library mode: In the teaching-oriented library mode, the role of librarians is not to answer questions, but to provide guidance for the research process, so the work of reference librarians is to discuss with users in a fixed field, rather than setting up a reference desk alone. 3. Continuous reference service: Reference service is divided into two or more service areas, and simple question-and-answer service is different from complex or in-depth consulting service. 4. Digital reference service: Internet-based question-and-answer service to contact users and experts in different disciplines.