Carbon/carbon (C/C) composites as high temperature structural materials have been widely used in aeronautics and astronautics because of their remarkable mechanical, thermophysical, and tribological properties. For the deep investigation of carbon deposition mechanism, newly developed approaches of fast densification of C/C composites have been indicated, such as thermal gradient chemical vapor infiltration (TCVI), pressure gradient chemical vapor infiltration (PCVI), electrified CVI (ECVI), and chemical liquid‐vaporized infiltration (CLVI). Multilayer coating system provides a new way for the long‐term antioxidation of C/C composites. Carbon nanotubes and nanofibers, forming the bridge between carbon fibers of micrometer size, could also further enhance the mechanical properties of composite materials. Bonded repair of C/C composite structure is used to extend the life of wear or underdesigned components and joins different components at a reasonable cost. All these studies promote the research and development of advanced C/C composites.