Abstract: In order to improve the bioactivity of the 3D braided carbon fiber reinforced PEEK composites (3D C/PEEK) used for high-performance hard tissue repair materials, the air plasma technology was used to treat the surface of the 3D C/PEEK, and then Ca-P layer on their surface was obtained through immersing in 1.5 times simulated body fluid (SBF) for 7 days. The effect of plasma treatment time on the surface appearance, hydrophility, chemical characterization and biomimetic deposition of the 3D C/PEEK was studied. The results show that the roughness, hydrophility and active groups of the 3D C/PEEK composite surfaces are improved with the increase of plasma treatment time. When 3D C/PEEK composite after plasma treatment is immersed in 1.5 times SBF for 7 days, the Ca-P layer would be formed on their surface, and the Ca-P layer of the 3D C/PEEK composite after plasma treatment for 120 s is more compact than that of after being treated for 30 s.