Nylon 6,6/PANI nanofibers using electrospun nylon 6,6 nanofibers as a template are synthesized by the in situ polymerization of different aniline concentrations for the preparation of all-polymer based core-sheath nanofibers with high electrochemical and mechanical properties, such as lightness and flexibility. These nylon 6,6/PANI based sheath nanofibers are used as electrode materials for supercapacitors. The electrochemical performance is examined by cyclic voltammetry (CV), galvanostatic charge/discharge tests and electrochemical impedance spectroscopy (EIS). The galvanostatic charge/discharge test reveals the highest specific capacitance of 665Fg−1 at a current density of 1Ag−1. This electrode also shows remarkable rate charge/discharge capability and high cyclic stability (62% after 1000 cycles). In addition, the high energy density of the nylon 6,6/PANI composite electrode can reach 91Whkg−1 at a power density of 500Wkg−1. The superior electrochemical properties of the core-sheath nylon 6,6/PANI nanofibers are attributed to their core-sheath structure, thin wall thickness and uniform wall distribution, which can improve the performance of electroactive PANI during the charge/discharge process. The good electrochemical performances highlight the potential of the nylon 6,6/PANI electrode as an electrode material for high-performance supercapacitors.