Its structure consists of a clamp body, a base, a guide nut, a lead screw, a clamp body and the like. The movable clamp body is in sliding fit with the guide rail of the fixed clamp body through the guide rail. The lead screw is installed on the movable clamp body which can rotate but cannot move axially, and is matched with the lead screw nut installed in the fixed clamp body. When the handle is shaken to rotate the lead screw, the movable clamp body can be driven to move axially relative to the fixed clamp body, so as to play the role of clamping or loosening. The spring is fixed on the lead screw with the help of retaining ring and cotter pin, and its function is to make the movable pliers withdraw in time when the lead screw is loose. Gang Qian are respectively installed on the fixed clamp body and the movable clamp body and fixed by screws. There are crossed net patterns on the working surface of the jaws, so the workpiece is not easy to slide after clamping. The jaws are hardened by heat treatment and have good wear resistance. The fixed clamp body is installed on the rotating seat and can rotate around the axis of the rotating seat. When rotating to the required direction, pull the clamping handle and tighten the clamping screw. Under the action of the clamping disc, the fixed clamp body can be tightened. There are three bolt holes on the rotating seat for fixing with the fixture table.