To enhance the specific capacity and cycling stability of manganese binoxide (MnO2) for supercapacitor, antimony (Sb) doped tin dioxide (SnO2) is coated on MnO2 through a sol-gel method to prepare MnO2 electrodes, enhancing the electrochemical performance of MnO2 electrode in sodium sulfate electrolytes. The structure and composition of SS-MnO2 electrode are characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-Ray diffraction spectroscopy (XRD). The electrochemical performances are evaluated and researched by galvanostatic charge-discharge test, cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS). The results show that SS-MnO2 electrodes hold porous structure, displaying superior cycling stability at large current work condition in charge-discharge tests and good capacity performance at high scanning rate in CV tests. The results of EIS show that SS-MnO2 electrodes have small internal resistance. Therefore, the electrochemical performances of MnO2 electrodes are enhanced effectively by Sb-doped SnO2 coating.