Abstract: Domestic polyacrylonitrile (PAN)-based M55J grade carbon fiber (CF) was electrochemically oxidized by cyclic voltammetry multi-scans in different electrolyte systems. The screening of the electrolyte was carried out by comparing the difference in oxidation capacity, and then CF was treated with the method of continuous constant-current anodic oxidation. The effects of electrochemical oxidation on the surface structure and chemical components of high strength and high modulus CF were studied by Raman spectroscopy, XPS and SEM. And the mechanical properties of CF were characterized by the tensile properties of the test beam and the interlaminar shear strength after bonding with the resin. The results show that NH₄HSO₄ electrolyte solution on the surface treatment of CF, can get the strongest etching ability, can effectively improve the surface activity of CF, increase the surface roughness and oxygen content of the number of functional groups. The CF is anodized at a current density of 1 mAcm^-2 using a 0.6 mol/L NH₄HSO₄ electrolyte system. The interlaminar shear strength between the CF and the resin is 164% higher than that of the untreated, while the tensile strength of CF is slightly improved and the modulus is not changed obviously.