<p>The favorable antibacterial properties of the orthopedic implants can effectively reduce the risk of postoperative bacterial infection. Herein, CuS/PEEK biocomposites with an excellent antibacterial activity were successfully prepared by the method of cold pressing in combining with sintering molding technology. The investigation on the antibacterial properties revealed that the CuS/PEEK biocomposites exhibited superior antibacterial ability against both <i>S. aureus</i> and <i>E. coli</i>, whose antibacterial rates were 99.87% and 99.89%, respectively, while the CuS content in the bicomposites was up to 5%. Moreover, The antibacterial rates of CuS/PEEK composites against <i>S. aureus</i> and <i>E. coli</i> were as high as 99.98% after bacterial strain and CuS/PEEK co-cultivation for 15 min under light irradiation, indicating that the light irradiation and CuS/PEEK composites have the synergistic effect on the antibacterial activity. The antibacterial mechanisms verified that the photo-thermal effect of CuS and the continuous release of Cu²⁺ and S^2- ions in the composites played an important role for the improving antibacterial activity of CuS/PEEK composites.</p> Graphical Abstract <p></p>