The invention discloses a worm-driven mechanical gripper. A driving module can drive a worm to rotate, a worm gear can be made to rotate in the worm rotating process, and then the degree of an angle formed by taking a first rotation shaft as a vertex point and taking a second rotation shaft and a fourth rotation shaft as end points is changed; a clamping surface can be displaced in the horizontal direction according to the parallelogram principle, and then clamping is achieved. According to the worm-driven mechanical gripper, driving components adopt simple connecting rod structures, therefore, the reliability is very high, and the life is very long; in addition, transmission of the worm gear and the worm is very precise, and therefore the worm-driven mechanical gripper can achieve precise gripping; meanwhile, transmission of the worm gear and the worm can achieve the effects of reducing the speed and increasing the torque and the clamping force. Therefore, the problem that the size and the mass are large due to the fact that a speed reducing mechanism needs to be additionally arranged on a mechanical gripper in the prior art is avoided. The worm-driven mechanical gripper is applied to the field of mechanical grippers.