Abstract: In order to improve the surface properties of domestic high-modulus high-strength carbon fibers and the interfacial properties of their composites, Ti₃C₂T_x MXene nanosheets were constructed on the surface of domestic high-modulus high-strength carbon fibers (BHM5 carbon fibers) using a continuous electrophoretic deposition process. The surface morphology, surface element content, surface wettability of BHM5 carbon fibers and the mechanical properties and cross-section morphology of their composites before and after modification were characterized by SEM, XPS, dynamic contact angle, and INSTRON universal material tester, and the interfacial enhancement mechanism of the Ti₃C₂T_x MXene-modified BHM5 carbon fiber composites was investigated. The results show that the surface roughness and specific surface area of the Ti₃C₂T_x MXene-modified BHM5 carbon fibers increase, possessing a good mechanical interlocking ability with the epoxy resin matrix. The content of polar groups on the surface of the carbon fiber increases significantly, and the surface wettability is enhanced. After treating the BHM5 carbon fibers at 15 V for 2 min, the interlaminar shear strength of the composites reaches 82.54 MPa, which is enhanced by 28.2% compared with the composites made of untreated carbon fibers.