A novel amine-based functionalization method was developed to improve the interfacial adhesion between TiO2 NWs and CFs in supercritical water. The microstructure, morphology and mechanical properties of CFs were investigated. It was found that introducing hexamethylenetetramine (HMTA) dendrimers and branched polyethyleneimine (PEI) on CF could increase significantly the adhesion strength between CF and TiO2 NWs and their interfacial shear strength with epoxy resin, and the order is CF-PEI-TiO2 NWs>CF-HMTA-TiO2 NWs>CF-COOH-TiO2 NWs>CF-TiO2 NW. Meanwhile, the reinforcing mechanisms and interfacial failure modes have also been discussed. We believe that these effective methods may provide theoretical foundation for the preparation of high performance composite materials.