The invention discloses a quick limit locking structure, comprising a base, a dovetail seat, a limit shaft and a
handle, wherein the upper part of the base is provided with a notch; the dovetail seat is arranged above the base and is slidably connected with the base, the
tail part is provided with a longitudinal groove, one side of the
tail part is provided with a cylindrical part, the end face of the cylindrical part is provided with a spiral surface, the limit shaft sleeve is arranged at the
tail part of the dovetail seat, one end is threadedly connected with the
handle, one side of the limit shaft is provided with a notch, one side of the
handle is provided with a boss, which cooperates with the spiral surface of the dovetail seat, and a locking pin is radially provided on the upper edge of the handle for stopping rotation when the handle is connected with the limit shaft. In a
natural state, the handle is in a vertical state, the boss of the handle is located at the lowest point of the spiral surface, the cylindrical surface of the limit shaft is separated from the notch of the base, and the dovetail seat can be slidably separated from the base. When limit locking is required, the handle is rotated, and the boss of the handle climbs from the low point of the spiral surface to the high point of the spiral surface to lock the dovetail seat and the base. After the handle is rotated 90 degrees, the boss of the handle is separated from the spiral surface, and at this time, the cylindrical surface of the limit shaft overlaps with the notch of the base to limit the sliding of the dovetail seat and the base.