The invention discloses a device for clamping eccentric parts, which relates to the field of machinery. In the existing mechanical working, when eccentric parts are processed, the operation of clamping the eccentric parts is difficult, the working accuracy is not easy to guarantee, and the qualification rate of finished products is low, therefore, the existing eccentric-part clamp device is not suitable for batch production. The device disclosed by the invention comprises a coupling disk, a mandrel, a clamp bolt, a stop pin, a counter-weight block, an open washer and a nut, wherein the mandrel is embedded in a hollow cavity of the coupling disk, the clamp bolt is in threaded connection with the mandrel, the open washer is used for adjusting the position of the mandrel relative to the coupling disk, the nut is used for fixing the coupling disk, the counter-weight block is used for balancing workpieces, and the stop pin is used for positioning. The device disclosed by the invention is an eccentric-part clamp device with a simple structure and easily-guaranteed working accuracy, and has the advantages of wide application scope, high operating efficiency, simplicity in installation, capability of being applied in batch production, and the like.