Abstract: The β-SiC fibers with high degree of crystallinity were obtained by electrospinning combined with carbothermal reduction method using tetraethyl orthosilicate (TEOS) as silicon source and polyvinylpyrrolidone (PVP) as spinning agent. The specific surface area of β-SiC fibers is 92.6 m²/g, which show the electric double layer capacitance. The specific capacitance of β-SiC fibers is up to 155.7 F/g. A large number of NiCo₂O₄ nanowires with a diameter of about 15 nm were grown on the surface of SiC fibers via hydrothermal method in order to obtain NiCo₂O₄ nanowires/SiC composite fibers. The results show that nickel and cobalt elements are present in the form of Ni²⁺/Ni³⁺ and Co²⁺/Co³⁺, respectively. The specific capacitance is significantly improved by the synergistic effect of NiCo₂O₄ nanowires and SiC fiber, and the NiCo₂O₄ nanowires/SiC composite fibers show both electric double layer and pseudo capacitance. The specific capacitance of NiCo₂O₄ nanowires/SiC composite fibers is up to 300.3 F/g. When the power density is 58.1 W/kg, the energy density of NiCo₂O₄ nanowires/SiC composite fibers is 60.1 W·h/kg.