Protective device for preventing road collapse

The utility model discloses a protection device for preventing road collapse, and belongs to the technical field of road protection, the protection device comprises a shell, the inner bottom wall of the shell is fixedly connected with multiple sets of threaded blocks, the interiors of the multiple sets of threaded blocks are in threaded connection with threaded rods, and the lower ends of the multiple sets of threaded rods rotationally penetrate through the bottom wall of the shell; the lower ends of the threaded rods are fixedly connected with conical blocks correspondingly. After the threaded rod is used, when the threaded rod is recycled, the threaded rod can be cleaned by a threaded wall on an arc-shaped block when the threaded rod rotates, an arc-shaped brush can clean a conical block, and then the arc-shaped brush and the arc-shaped block can stretch out and draw back under the cooperation of a telescopic rod and a spring; the arc-shaped blocks and the arc-shaped brushes can conveniently clean the threa