Abstract: In recent years, "Internet +" has been stretched into every walk of life, which accelerates the industrial transformation across areas in China. As other fields, public library are also facing the quick changes of users' demands. Based on the concept of "Internet +", cloud-library project has become the important tool for public library to meet the opportunities and challenges of reader service and conform to the development of public library 3.0. This paper discussed the digital platform construction, collection planning and digital resources circulation, and tried to display the basic framework system of the cloud-libary project.