O2O closed-loop is an important strategy for O2O companies to gain traffic growth and users retention to achieve sustainable development. Information flow is an important component in the closed loop, and the development of digital intelligence technology is an important driving force for the closed loop. Focusing on the O2O information flow closed-loop strategy enabled by digitalization and intellectualization, this paper first explains the connotation of information flow in O2O commerce. Then, the closed-loop path of O2O information flow is analyzed, which is consists of six units, and a theoretical model is proposed. Furthermore, taking Koubei as the case study object, the digital measures of Koubei in implementing the closed-loop strategy are analyzed. Finally, this paper points out that academic research on O2O closed-loop is still relatively limited and deserves further attention from scholars.