Metaverse is the hottest focus topic in the current Internet field, which can provide heuristic theories, methods and technologies for the construction and development of libraries in the future. This paper discusses the origin, connotation and characteristics of the integration of library and metaverse theory, designs and constructs the corresponding system structure, explains it from the aspects of integration structure, elements, technology and ability, and then analyzes its development trend. The research shows that the library metaverse, as one of the important components of the metaverse, can fully perceive the human, machine, material, environment and other elements of the library and their relationship with each other, so as to realize the effective connection between the library physical world and the metaverse space.