The invention provides a sealing device for a super capacitor, and the device comprises an end cover and a sealing ring. The end cover comprises a circular substrate and a circular boss. The sealing ring comprises an annular ring body, a first circular insulating edge, and a second circular insulating edge. The sealing ring sleeves the end cover, and the first circular insulating edge covers the side edge of the circular boss. The annular ring body abuts against the top surface of the circular substrate, and the second circular insulating edge covers the side surface of the circular substrate. The device can effectively prevent the liquid leakage of the super capacitor, and enables the quality of the super capacitor to be improved.