An increase in demand for highly efficient electrochemical energy storage devices has led researchers to search more on electrode material with a simple synthesis process. In this research work, we a report simple chemical oxidation polymerization method to synthesize a ternary nanocomposite i.e., SnO2/RGO@PANi by embedding tin oxide (SnO2) and polyaniline (PANi) on reduced graphene oxide (RGO). The structural and morphological properties of the prepared composite was analyzed by X-ray diffraction spectrum (XRD), Raman spectroscopy Field emission scanning electron microscopy (FESM) and Fourier transform infrared spectroscopy (FTIR). Further electrochemical characterization were studied using a cyclic voltmeter (CV) and Galvanostatic charge–discharge (GCD) analysis. The SnO2/RGO@PANi composite exhibits a better specific capacitance of (366.30F g−1) and energy density of (147.92 Wh kg−1) at a current density of 1 A/g. Due to the synergic effect of SnO2, RGO, and PANi nanocomposite, it showed a better electrochemical performance including cyclic stability of 88% retention for 50 cycles. Therefore, the SnO2/RGO@PANi nanofiber (NF) composite can be considered a promising electrode material for the application of supercapacitors.