Improved waterproof opposite-pull screw convenient for mounting and dismount for wall

The utility model discloses an improved waterproof opposite-pull screw convenient for mounting and dismounting for a wall. The improved waterproof opposite-pull screw comprises opposite-pull inner supporting pipes which are provided with inner supporting pipe blocking supporting caps and pull rods at two ends; and nuts are arranged on the pull rods. The improved waterproof opposite-pull screw is characterized in that a waisted part is arranged between the opposite-pull inner supporting pipes, and the diameter of the waisted part is less than that of each opposite-pull inner supporting pipe; and a water stop ring is mounted on the opposite-pull inner supporting pipe at one side of the waisted part. The waterproof opposite-pull screw is improved in that the pull rods are provided with a plurality of gap groups; and compressing devices, which are structured as a plurality of concave grooves positioned in two end parts of the opposite-pull inner supporting pipes, are respectively arranged at two end parts of the