The utility model provides a protection device that falls is prevented to broken string, it includes a plurality of gangs of preformed armor rods that are made by aluminium alloy material, the section of holding with a firm grip the in bank that its both ends are the coiled tubular shape structure sticks together, and evenly be stained with electrically conductive sand on the inner wall of coiled tubular shape structure, the transposition section that is the linearity among them twines burst transposition together, the burr processing of polishing is all done at preformed armor rods's both ends, use, at first lead according to what be suitable for, the quantity that takes shape and confirm required the device is prefabricated to the ground wire specification, it leads to install the sign alignment with the center during installation, the ground wire center of hanging, make the transposition section be on a parallel with suspension clamp, twine the section of holding with a firm grip at both ends in proper order again and leading, on the ground line, it takes one's place to ensure the straining of preformed armor rods both ends, the protection device that falls is prevented to broken string installation in proper order that to install, messenger's section of holding with a firm grip zero clearance can. Its simple installation, uniformity are strong, but long -time running moreover, non -maintaining, energy -efficient has been solved the overhead transmission line broken string and has been fallen the influence and strideed across the difficult problem of thing safe operation.