The invention discloses a wrench with the adjustable caliber. The wrench comprises a wrench body capable of screwing bolts or nuts, and a hand shank connected with the wrench body. The wrench body comprises push rods, a base and a transmission mechanism for adjusting motion of the push rods. The vertical side of the base is provided with threaded holes in one-to-one correspondence with the push rods, the threaded holes are in threaded connection with the push rods, the transmission mechanism drives the push rods to rotate, and the push rods rotate forwards through cooperation with the threaded holes. According to the wrench, an adjusting screw rod is used for driving a rotary base plate to rotate, then the push rods are driven to move, the push rods can complete radial motion through restraint of the threaded holes on the push rods, the push rods rotate forwards along the threaded holes, a self-locking effect is achieved after a target is clamped, and slipping is not liable to occur; and large clamping force and screwing supporting force can be provided, so that damage, caused by excessively large screwing force, to a tool is reduced.