A superconducting cable terminal device for connecting a current lead arranged at an ambient temperature and a superconducting cable with a cryogenic refrigerant container in which it is arranged, whereby the device comprises: a connecting unit including the current lead and the superconducting cable and being formed by connection thereof; a solid insulation bushing being formed at an outside of the connecting unit; a refrigerant inflow circulation path being formed in the solid insulation bushing and allowing the refrigerant to enter thereinto; a refrigerant outflow circulation path being formed in the solid insulation bushing to correspond to the refrigerant inflow circulation path and connected to the refrigerant inflow circulation path and connected to the refrigerant container or outlet to allow entered refrigerant to exit to the refrigerant container or to the outside, forming a refrigerant passage having high-voltage insulation characteristics and cooling the connecting unit by being formed outside the current lead or passing through the current lead; and a current lead cooling circulation path passes through in a helically bent coil shape along an axis of the current lead on the inner side of the bushing, wherein the current lead cooling circulation path is connecting the refrigerant inflow circulation path and the refrigerant outflow circulation path at a location between the circulation paths, and the refrigerant inflow circulation path and the refrigerant outflow circulation path pass through in a zigzag shape from an outside surface of the insulation bushing toward a center thereof, wherein, beneath the solid insulation bushing, a reinforcing insulator is provided to enclose a section where the superconducting cable and the current lead are connected to each other and wherein the current lead includes: an ambient temperature current lead being connected to an external connecting terminal; an upper current lead being provided by coupling with the ambient temperature current lead and extending downward; and a lower current lead having one end connected to the upper current lead and an opposite end coupled with the superconducting cable. a connecting unit including the current lead and the superconducting cable and being formed by connection thereof; a solid insulation bushing being formed at an outside of the connecting unit; a refrigerant inflow circulation path being formed in the solid insulation bushing and allowing the refrigerant to enter thereinto; a refrigerant outflow circulation path being formed in the solid insulation bushing to correspond to the refrigerant inflow circulation path and connected to the refrigerant inflow circulation path and connected to the refrigerant container or outlet to allow entered refrigerant to exit to the refrigerant container or to the outside, forming a refrigerant passage having high-voltage insulation characteristics and cooling the connecting unit by being formed outside the current lead or passing through the current lead; and a current lead cooling circulation path passes through in a helically bent coil shape along an axis of the current lead on the inner side of the bushing, wherein the current lead cooling circulation path is connecting the refrigerant inflow circulation path and the refrigerant outflow circulation path at a location between the circulation paths, and the refrigerant inflow circulation path and the refrigerant outflow circulation path pass through in a zigzag shape from an outside surface of the insulation bushing toward a center thereof, wherein, beneath the solid insulation bushing, a reinforcing insulator is provided to enclose a section where the superconducting cable and the current lead are connected to each other and wherein the current lead includes: an ambient temperature current lead being connected to an external connecting terminal; an upper current lead being provided by coupling with the ambient temperature current lead and extending downward; and a lower current lead having one end connected to the upper current lead and an opposite end coupled with the superconducting cable. an ambient temperature current lead being connected to an external connecting terminal; an upper current lead being provided by coupling with the ambient temperature current lead and extending downward; and a lower current lead having one end connected to the upper current lead and an opposite end coupled with the superconducting cable.