innovation has become a norm and transformation has become a topic of the times. Libraries need to take the initiative to transform. Under the guidance of the new theory, libraries need to build a suitable field for knowledge innovation, provide more convenient resources, develop intelligent situational services, and establish a new paradigm of knowledge services to complete the transformation of libraries. Library transformation is a system. In addition to the profound influence of social environment and industry environment beyond the system, external and internal driving forces exist, which form a joint force to promote the transformation and development of the library. Technology driven and demand driven are external driving forces of library transformation, which have indirect and profound impact on the transformation; innovation driven is the internal driving force of library transformation, and the impact on the transformation is direct and more profound. In the post knowledge service era, library transformation is composed of four elements: space, resources, services and management. The transformation of elements is not only an important change for specific elements, but also a fundamental change to promote the overall transformation of libraries. The overall transformation, which is related to the target orientation of the next generation of libraries, is the result of the transformation of the four elements. In the post knowledge service era, the transformation of libraries not only needs to solve problems in internal and external principles, but also problems in concepts, key elements and path. In addition to the concept of knowledge, the most important things in library transformation are the concepts of data and wisdom. Every key element of library transformation has leeway in innovation. Innovation promotes change, and change promotes transformation. Three aspects must be considered in library transformation: setting up library scenario planning; establishing internal innovation driving mechanism of library transformation; starting from the transformation of elements, adjusting measures to local conditions and realizing the overall transformation of libraries through the transformation of all elements. 2 tabs. 57 refs.