The utility model discloses a broken line connecting device, and the device comprises a conductor, a protection layer, and a fastening apparatus. The conductor is provided with a copper rod, a contact hole, a circular clamping board, and a central clamping groove. The protection layer is provided with an insulating sheath and a central boss. The fastening apparatus is provided with a plug pipe, a clamping board groove, a pressure plate, an insulating soft plug, and a threading hole. The device is simple in structure, is convenient to operate, can quickly enable a wire core to be connected, and saves the tedious installation process. The soft contact enables the whole device to be good in airtightness and waterproof capability after wiring.