Pneumatic chuck applied to stretch bending and straightening belt

The utility model discloses a pneumatic chuck applied in stretch bending and straightening threading, which comprises a main body pneumatic chuck, a pneumatic chuck matrix, a threading system accessory, a copper strip and an S roller, the main body pneumatic chuck is arranged on the inner side of the pneumatic chuck matrix, the main body pneumatic chuck is arranged on the threading system accessory and the copper strip, and the S roller is arranged on the main body pneumatic chuck. The strip threading system accessory and the copper strip are wound on the S roller, an upper pressing plate is positioned on the pneumatic chuck matrix, small clamping plates are arranged at the two ends of the pneumatic chuck matrix, the side of the pneumatic chuck matrix is connected with a pneumatic quick connector, guide strips are positioned on the small clamping plates, threaded columns are positioned on the guide strips, and the threaded columns are connected with the pneumatic quick connector. And an upper pressing plate i