The present invention belongs to the technical filed of straw or forage harvesting and bundling, especially a dual chain ring driving knotting machine which includes a small chain ring, a knotting machine support, a large chain ring, a knife arm, a winding, buckling, clamping and occluding mechanism R, a rope clamping machine J and a rope clamping machine drive mechanism Q. The small chain ring and the large chain ring are coaxially mounted at both ends of the knotting machine support; the rope clamping machine drive mechanism Q and the winding, buckling, clamping and occluding mechanism R are mounted at different sides of the knotting machine support; in the knotting machine support, a knotting mouth shaft hole shaft axis d presents non-orthogonal concurrent axis arrangement with a knotting machine main shaft axle hole shaft axis a, a worm shaft axle hole shaft axis c presents perpendicular concurrent axis arrangement with the knotting machine main shaft axle hole shaft axis a, a knife arm shaft axle hole shaft axis b presents space orthogonal arrangement with the knotting mouth shaft hole shaft axis d, the knife arm shaft axle hole shaft axis b, the rope clamping plate shaft hole shaft axis e and the knotting machine main shaft axle hole shaft axis a are arranged space perpendicularly to each other; the dual chain ring driving knotting machine has reasonable structure, is easy for processing and assembling, and has low manufacturing cost, and reliable knotting characteristics.