The interconnected polyaniline coated carbon nanofiber (PANI/CNF) composite nanowire, with interconnected N-doped carbon nanofiber (CNF) framework and PANI coating layer, had been synthesized via a vacuum-assisted intercalation in-situ oxidation polymerization method. The PANI/CNF composite nanowire samples were characterized by TEM, SEM, TG, FTIR, Raman, XRD, XPS and BET. The electrochemical properties of the samples were examined using CV, EIS, and GCD. The results showed that the interconnected PANI/CNF composite nanowire with the hierarchical structure in the shape of thorns. As supercapacitor electrode materials, the typical PANI/CNF40 sample with CNF content of 40%, had a high specific capacitance of 820.31 F/g (1.0 A/g), and specific capacitance retention rate of 74.8% (20.0 A/g). The specific capacitance was 89.7% of the initial specific capacitance after 2000 cycles (10.0 A/g).