The invention provides a method for classifying battery pole pieces. In the method, a computer is used for control, classification is carried out based on the weights of pole pieces, and a mechanical arm is used to automatically pick, classify and receive the pole pieces. The invention also provides a system for realizing the classification method. In the system, a central control part is respectively connected with a mechanical arm, a feeding device, a receiving device and an electronic weighing device, wherein the mechanical arm is provided with a pneumatic sucking unit, and the feeding device, the electronic weighing device and the receiving device are installed in the same work box; and cases of the feeding device and the receiving device for containing the pole pieces are respectively provided with an opening which can enable a position sensor to sense signals. The classification method realizes the full automatic control on classification, eliminates human factors, and can greatly improve the efficiency and the accuracy of classification. Simultaneously, the classification method has an accurate design in the height range of positions of the pole pieces, can effectively prevent the pole pieces from being damaged in the classification process, and is beneficial to realizing the full automatic control method. The structural design of the system is simple and reasonable.