Nanocomposites exhibit very different physicalchemical properties from traditional materials because of small size effects, quantum effects, and surface interface effects. In nanocomposites, the interface has the characteristics of high surface interface content, large free energy, and strong reactivity. Therefore, the interface has more significant impact on the service, failure and fracture of the material. In order to achieve precise control of the properties of nanocomposites, interfacial structure design has become the focus of research. Nanocomposite interfaces, including physical bonding interfaces, reactive bonding interfaces, and transition layer bonding interfaces, have been extensively studied. The preparation methods and interfacial structure characteristics of nanocomposites are summarized in this paper, and the interfacial interaction is discussed in depth from three aspects of microstructure interaction, precipitation interaction and load transfer. Based on the structure features of interface, the strengthening mechanism and fracture behavior of nanocomposites are comprehensively summarized and analyzed. Whats more, the future development of nanocomposites is also forecasted.