Reading is the flow of knowledge,and so is librarians’work on reading promotion.It is necessary to communicate,learn and share among librarians,librarians and libraries,and libraries.The paper expounds the background,communication,visit and inspiration of the activity"Colorful Cloud Tour"in August,2019 in the Yunnan University Library,and demonstrates that reading promotion of librarians is"the flow of knowledge"from the aspects of knowledge space construction,knowledge collaboration of social networks,tacit ...