The invention is an organic ultracapacitor, comprising a shell body, a winding core assembly, electrolyte, an upper cover arranged above the opening side of the shell body, and a connecting piece arranged between the upper cover and the shell body; wherein, the positive and negative terminals of the capacitor are lead out from two sides thereof; the outer side of the shell body is connected with a capacitor terminal; the terminal and the shell body are connected with the upper cover by laser welding or resistance welding or casting moulding; the connecting piece is arranged between the capacitor core assembly and the upper cover, one side of the connecting piece is provided with a thread or bayonet structure and is connected with the upper cover, and the other side thereof is connected with the core assembly via laser welding; the welding areas of the core assembly and the inner side closed end of the shell body, and the core assembly and the connecting piece are 5-70%; the electrolyte is organic solution of tetraethylammonium tetrafluoroborate or organic solution containing lithium ion. The invention has the advantages of lowering the internal resistance of the organic ultracapacitor and improving the safety performance and service life thereof greatly.