Electric resection ring with variable-size electrode

The invention discloses an electric resection ring with a variable-size electrode. The electric resection ring comprises the electrode, delivery pipes and leads, wherein two ends of the electrode are connected with the leads and enter the delivery pipes from openings in the front ends of the delivery pipes, and the leads penetrate the delivery pipes and extend out from the tail ends of the delivery pipes. The electric resection ring can enter the operation position from the relatively small operation entrance, the size of the electrode of the electric resection ring is variable, and the tissue with the relatively large size can be cut only after a few times of resection; since the electrode is made of an elastic material with certain strength and toughness, the extension length of the electrode from the delivery pipes can be controlled by stretching the leads, and therefore, the size of the electrode is adjusted.