The utility model provides a cable access device of dielectric loss check out test set, including two cable joint, the cable joint includes that insulating layer sleeve pipe, the screw thread of cylinder compresses tightly set, insulation protection cover and the core bar that electrically conducts, insulating layer sheathed tube one end pipe wall top spin has closed two locking bolts, the terminal equal rotary type of screw rod of two locking bolts is equipped with an arc cover plate, and the intrados of two arc cover plates is relative, on the electrically conductive core bar of the fixed cover disposed on of insulation protection cover, and be equipped with the protruding circle of round on the outer circumference at insulation protection cover middle part, the end rotation that the screw compressed tightly the cover closes on the insulating layer sheathed tube other end, and the insulation protection cover is inserted in the screw compresses tightly the cover, and the screw compresses tightly the protruding circle of other end grasping that overlaps, outside the terminals of electrically conductive core bar projected the insulation protection cover, it is intraductal that the contact jaw stretches into the insulating layer cover. The cable access device can fast and not have the ground of destruction access detected cable, and not only the structure is reliable but also the contact is good, has better application prospect.