In order to protect and repair fragile silk cultural relics and prolong their life, try to study a new type of biological material to strengthen and protect aging silk, and explore the strengthening mechanism. In this study, silk fibroin/carboxymethyl chitosan (SF/CMCS) composites were prepared using silk fibroin (SF) and carboxymethyl chitosan as raw materials, and transglutaminase as cross-linking agent, and were applied Reinforced protection from aged silk. Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), colorimeter, scanning electron microscope (SEM) and servo tensile tester were used to characterize the effect of aged silk before and after reinforcement. The research results show that the SF/CMCS composite material has good compatibility with the aged silk, the appearance of the reinforced silk has no obvious change, the mechanical properties are significantly improved, and it has certain antibacterial properties. It is proved that SF/CMCS composite material is a safe and effective reinforcement material, which lays a certain foundation for the protection and restoration of silk cultural relics in the later period.