To provide a tire anti-skid tool tightening device which is inexpensive because of a simple structure, is small, and allows easy maintenance.

This tightening device has a take-up reel 21, having a pair of flanges formed at a predetermined interval to each other in approximately the longitudinal center of a shank to wind a tightening rope 6 on the shank between the flanges, and an outside support member 17 having a pair of side plates connected thereto and held in place at a predetermined interval and parallel to each other, with both ends of the shank freely rotationally supported on the side plates to mount the take-up reel between the side plates. Ratchet teeth 28 designed to idle in the winding direction and to engage in the opposite direction are formed on the outer periphery of the flange of the take-up reel, a lock piece 13 that can be engaged with and disengaged from the ratchet teeth is mounted between the side plates of the outside support member, and a spring member 32 which activates and presses the lock piece against the ratchet teeth of the take-up reel is provided.