The utility model relates to a follow -on chain structure, including outer chain plate, inner plate, round pin axle and gyro wheel, outer chain plate and inner plate are inside and outside to be set up, the round pin axle passes inner plate and outer chain plate to stretch out outside outer chain plate respectively at the both ends of round pin axle, the both ends of round pin axle are overlappedrespectively and are equipped with a gyro wheel, the cover is equipped with a bearing between gyro wheel and the round pin axle. The utility model has the advantages of through install the bearing inthe gyro wheel, adopt rolling style to replace traditional slip mode, the power of reducing friction to reducing wear improves chain transmission efficiency.