The utility model discloses a guide rail falls line element insertion part from extension, it puts recess, the 2nd groove structure, permanent magnet and first protruding structure to put recess, a groove structure, baffle, the protruding structure of second, dog, second card including the scarf joint body, scarf joint groove, first card, the one end of the scarf joint body is equipped with the scarf joint groove, the adjacent both ends face of the scarf joint body is equipped with protruding structure of second and first protruding structure respectively, the other adjacent both ends face of the scarf joint body is equipped with that the recess is put to first card and the recess is put to the second card, and first card is put recess and second card and is put and be equipped with a groove structure and the 2nd groove structure in the recess, first card is put recess and second card and is put the one end of recess and be equipped with the dog, the terminal surface of dog is equipped with the permanent magnet, first card is put recess and second card and is put the top that the recess is lieing in the permanent magnet and be equipped with the baffle. The utility model discloses, can realize thorough preventing falling from the effect, can play the fixed action in all directions, connect more stably, in the aspect of the confinement, have obvious advantage.