Corrosion-resistant butterfly valve

The invention discloses a corrosion-resistant butterfly valve, and relates to the technical field of valves, the corrosion-resistant butterfly valve comprises a valve body, the valve body is provided with a water through hole for water to pass through, one end, facing a pipeline, of the valve body is provided with a mounting groove surrounding the water through hole, the valve body is provided with a mounting ring, and the mounting ring slides in the mounting groove; at least three correcting columns are arranged on the side, facing the notch of the mounting groove, of the mounting ring at intervals in the circumferential direction, and the correcting columns are hinged to the mounting ring and can turn over in the direction away from the central axis of the mounting ring. A pre-positioning ring for allowing the bolt to penetrate through is arranged on the peripheral side of the valve body, the valve body is provided with a driving part for driving the mounting ring to protrude out of the mounting groove towa