The utility model discloses a special-purpose conducting wire back-up protection device for replacing a tension insulator. The special-purpose conducting wire back-up protection device for replacing the tension insulator comprises a tapered shell and a tapered block arranged in the tapered shell, and rotating shafts are arranged between the tapered shell and the tapered block. One ends of the rotating shafts are equipped with gears respectively, and the other ends are equipped with a bearing strength connecting member. Tooth sockets are arranged in the tapered block, and the gears are arranged in the tooth sockets. The tapered shell is equipped with a through hole, and the tapered block is equipped with a conducting wire groove. According to the utility model, the situation of using the rotating shafts to adjust the in and out of the tapered block in the tapered shell is realized effectively, the clamping degree of the conducting wire is convenient to adjust via the rotating shafts, and the fastening performance, safety and reliability of the special-purpose conducting wire for replacing the tension insulator are guaranteed greatly. By arranging the conducting wire groove in the tapered block, the contact area of the conducting wire and the tapered block is increased greatly, and the conducting wire is prevented from deforming and slipping.