An adjustable corrector for preventing and treating ingrown nails is characterized in that an arc-shaped nail traction piece is arranged, fixing hooks bent downwards are arranged at the two ends of the traction piece, the nail traction piece is divided into a movable piece and a fixed piece, a row of ruler holes are evenly distributed in the movable piece, an adjusting end is arranged at the end, overlapped with the movable piece, of the fixed piece, and the adjusting end is connected with the movable piece. An adjusting screw is fixed in the adjusting end, the end, not provided with the fixing hook, of the movable piece is inserted into the adjusting end, threads of the adjusting screw are meshed with the ruler hole in the movable piece, translation of the movable piece is controlled by rotating the adjusting screw, and therefore the whole nail traction piece can stretch and retract.