Abstract: Surface-nickeled polyimide (PI-Ni) fibers with high tensile strength, high conductivity and high-temperature stability were successfully prepared by using high-strength PI fiber as the matrix via a surface-modification ion-exchange and electroless nickel plating method. The prepared PI-Ni fibers were characterized by SEM, XRD, EDS, mechanical test, electrical conductivity measurement, adhesion test and TGA, respectively. The results indicate that the coated metal layer on the PI-Ni fibers is amorphous Ni-P alloy, which has smooth, detect-free and compact surface morphologies. The PI-Ni fiber is prepared with the tensile strength up to 1.2 GPa, surface resistivity of 1.76×10^-4 Ω·cm, and 5%-weight-loss temperature of 611℃, which is a high-performance organic conductive fiber.