The invention is applicable to the field of article conveying equipment, and discloses a transmission belt connecting piece and a transmission belt module. The transmission belt module comprises the transmission belt connecting piece, the transmission belt connecting piece comprises connecting piece bodies, rotating shafts connected to the connecting piece bodies and balls connected with rotatingshafts, a plurality of mounting grooves are formed in the connecting pieces in a penetrating mode, each mounting groove is provided with the plurality of balls, each mounting groove is provided with afirst groove surface, a second groove surface, a third groove surface and a fourth groove surface, first arc-shaped parts consistent with the balls are concavely arranged at the parts, facing away from the fourth groove surfaces, of the third groove surfaces, second arc-shaped parts consistent with the balls are arranged at the parts, facing away from the third groove surfaces, of the fourth groove surfaces, the plurality of balls are arranged between the first arc-shaped parts and the second arc-shaped parts, the first arc-shaped parts and the second arc-shaped parts can provide support force for the balls, and the balls are prevented from being directly suspended in the mounting grooves, so that the pressure resistance strength of the balls is enhanced, the situation of large deformation of the balls is reduced, and articles are smoothly conveyed favorably.