The invention relates to a belt driving rotating mechanism of a threshing cylinder concave assembly for a threshing machine and belongs to an agricultural machinery. A ring-shaped belt ring is fixedly mounted at the end part of the threshing cylinder concave assembly; a plurality of hinge pins are uniformly distributed and assembled on the ring-shaped belt ring in the peripheral direction; rolling bearings are respectively mounted at the end parts of the plurality of hinge pins at the same side; rolling supporting ring seats are fixedly arranged at the side part of the ring-shaped belt ring, are positioned with the ring-shaped belt ring in the radial direction, circumferential direction and axial direction and are concentric; the rolling bearings are positioned in ring-shaped rolling chutes of the rolling supporting ring seats; a driving belt pulley is configured at the side part of the ring-shaped belt ring; a driving belt sleeves the driving belt pulley and the ring-shaped belt ring. The mechanism implements the rotating operation of the threshing cylinder concave assembly, is novel, simple and reasonable in structure, is reliable to use, is high in quality of the threshing operation and is high in production efficiency.