The challenge of incorporating photothermal conversion function into chitosan (CS) hybrid fibers lies in balancing functionality and mechanical properties. In this study, we successfully prepared a chitosan/graphene oxide/gelatin (CS/GA/GO) hybrid fiber using the wet spinning process, achieving improved mechanical properties and efficient photothermal conversion capabilities. When compared with pure CS fiber with a breaking strength of 1.07 cN/dtex, the breaking strength of the CS/ GA composite fiber increased by 46.73%, while the CS/GA/GO hybrid fiber showed an even greater increase of 85.98%. In addition, the introduction of gelatin (GA) led to secondary scattering of near-infrared light, enhancing the photothermal conversion efficiency. As a result, the CS/GA/GO hybrid fiber exhibited a faster temperature rise rate and higher maximum temperatures (94.3 °C, 103.0 °C, and 111.3 °C) as compared to the CS/GO hybrid fiber. The successful incorporation of GA not only improved the mechanical properties but also enhanced the photothermal performance of the hybrid fiber.