The present disclosure relates to an electrode for supercapacitor, preparation method and use thereof. The electrode comprises an electrode terminal, an active layer and a coating layer from inside to outside. A material for preparing the coating layer comprises an oxygenated compound, which contains at least one of transition metal elements or is doped with a substance containing a transition metal element. Providing the coating layer on the surface of the active layer prevents organic electrolytes from being easily adsorbed and nucleated in the porous structure of the electrode surface due to interface defects and facilitates to weaken the interface problems existing between the electrolyte and the electrode surface. The capacitor prepared by means of the electrode according to the embodiments of the present disclosure can significantly increase the operating voltage window (may be up to above 4V) and capacitance of the supercapacitor, and further increase energy density thereof.