The library community has formed two different interpretations of the second paragraph of article 29 of the People's Republic of China Public Library Law. This article starts from the legal text and library practice, through the interpretation of the meaning of the text, historical interpretation, purpose interpretation, system interpretation, sociological interpretation methods and the application of the proportionality principle, article 29 is interpreted legally. It also analyzes how to interpret the People's Republic of China Public Library Law in the process of legalization of public library.