The invention relates to a clamp. The clamp comprises a base, a rotary body, multiple levers and a drive mechanism. The rotary body comprises a bottom disc rotationally embedded on the base and a top disc connected with the bottom disc. A round hole matched with a workpiece is formed in the circle center of the top disc. A station suitable for inserting of the workpiece is formed in the area, from the bottom disc to the round hole in the axial direction, of the rotary body. Each lever is provided with a first end and a second end opposite to the first end, each first end is movably arranged on the base, each second end is connected with the bottom disc, and the multiple levers are arranged between the base and the bottom disc at intervals. The drive mechanism is connected with the bottom disc so as to drive the bottom disc to rotate relative to the base, and after the bottom disc rotates around the first direction by a preset angle, the second ends of the multiple levers abut against the circumferential wall of the workpiece inserted into the station so as to clamp the workpiece. The above clamp is simple and compact in overall structure and small in occupied space, clamping operation of the workpiece is convenient, and clamping efficiency is high.