The invention discloses a limiting and looseness-preventing type overload protective clamp, and belongs to the field of clamps. The limiting and looseness-preventing type overload protective clamp comprises a clamp base, a left fixing block, a left
threaded rod, a left clamping block, a right clamping block, a right
threaded rod and a right fixing block, wherein a dovetail groove is formed in the clamp base, and the left fixing block and the right fixing block are arranged at the two ends of the dovetail groove respectively. The limiting and looseness-preventing type overload protective clamp further comprises a safety
clutch mechanism, a fixed base, an adjusting rod, an outer ring, screws, springs, steel balls, a square
handle and limiting and looseness-preventing devices, wherein the limiting and looseness-preventing devices are arranged on the adjusting rod and the left
threaded rod respectively, the adjusting rod is assembled in a threaded hole of the fixed base, the square
handle is connected with the adjusting rod, the screws are assembled in threaded holes of the outer ring, the steel balls are pressed on the surface of the square
handle, and each spring is arranged between the corresponding screw and the corresponding
steel ball. The limiting and looseness-preventing type overload protective clamp solves the problems that according to an existing clamp, clamping force cannot be easily controlled, and looseness can be easily caused, and has the advantages of being simple in structure, reasonable in design and easy to manufacture.