Abstract: To improve the interfacial bonding performance between carbon fibers and different types of resins and to functionalize the carbon fiber surface without affecting its intrinsic properties, electron beam irradiation was employed to modify high-strength carbon fibers in air atmosphere. By adjusting the absorbed dose (50, 100, 500, 1000, 2000 kGy), the effects on the surface chemical properties and structure of carbon fibers were systematically investigated.The results showed that air electron beam irradiation mainly changed the near-surface structure and chemical properties, without affecting the overall crystal structure of carbon fibers.It introduced abundant oxygen-containing functional groups onto the carbon fiber surface, while causing no damage to the mechanical properties of carbon fibers. Specifically, at an absorbed dose of 2000 kGy, the oxygen-to-carbon ratio on the carbon fiber surface increased to 0.29, and the water contact angle decreased from 119.0° to 21.1°. The interfacial shear strength of carbon fiber/epoxy and carbon fiber/nylon 6 composites increased by 71.0% and 57.9%, respectively, compared with untreated fibers. This work provides a basis for the surface modification process of carbon fibers and the design and preparation of high-performance composites.