A high-strength and high-modulus PVA/CNF/GO composite fiber was prepared by wet spinning and hot drawing process. The reinforcement effect of cellulose nanofibrils (CNF) and graphene oxide (GO) on polyvinyl alcohol (PVA) fiber was studied, and the effects of CNF content and hot drawing temperature on the tensile properties of fibers were discussed. When the content of CNF is 6% and the content of GO is 1%, the PVA/CNF/GO composite fiber prepared by wet spinning has excellent tensile properties after three times of hot stretching treatment at 160 ℃. Its ultimate tensile strength and elastic modulus are (1.09±0.11) GPa and (21.87±3.03) GPa, respectively, which are 45% and 63% higher than those of pure PVA fiber, and 523% and 271% higher than those of PVA/CNF/GO composite fiber without hot stretching treatment. Meanwhile, the prepared composite fiber shows good biocompatibility. It can be used as surgical sutures to provide appropriate tension for tissue regeneration, demonstrating potential biological application value.