On June 27th in 2022, the 11th Urban Forum was opened in Poland with "Promoting Urban Transformation and Constructing Beautiful Future as its theme. On the first day, IFLA issued its report Library and Urban Renewal, Rejuvenation and Transformation in which library's function in urban development, which is long and potential but also easy to be missed, was proved and stressed through concluding and straightening out the literatures concerning library in the study of urban development. In this paper the author interpreted the background, key content and relevant enlightenment of the report and put forward that urban library should broaden our vision in theoretical study, take the development of the city as our duty, and increase our capacity in the service for the city.