Abstract: A cold snare includes a spring tube, a drive wire, and a loop. The cable passes through the spring tube, and can perform reciprocating motion in a direction of a longitudinal axis of the spring tube. The loop is fixedly connected to a distal end of the drive wire. Therefore, when the drive wire performs reciprocating motion in the direction of the longitudinal axis of the spring tube, the loop synchronously performs reciprocating motion in the direction of the longitudinal axis of the spring tube along with the drive wire to achieve the purpose of controlling the loop to enter and exit the spring tube by the drive wire. By using a spring tube as an outer tube, the strength of the spring tube is higher than that of a plastic outer tube of an existing cold snare, which is helpful for the loop to cut when grabbing large polyps.