The invention provides a large-current test connection device which comprises a hexagonal nut and a large-current test connection clamp, wherein the hexagonal nut is arranged on a hexagonal screw connected with a detection body in a sleeving manner, and an extension part is arranged on the hexagonal nut; the large-current test connection clamp is clamped on the extension part for a detection device to detect. As the hexagonal nut is arranged on the hexagonal screw in a sleeving manner, the extension part is arranged on the hexagonal nut, and the large-current test connection clamp is clamped on the extension part, the large-current test connection clamp is convenient to clamp and hard to fall off and is not required to be held by hands, so that operation personnel cannot touch a live part, that is, the safety during test is improved; meanwhile, as hand holding is avoided, and the large-current test connection clamp cannot shake, tested data is accurate.