Abstract: When the throughput of a single passage S-shaped elevator in a carton conveying system exceeded 50 cartons/minute, a series of problems might occur, including: accelerated chain plate wear, carton corner crease, BOPP film scratch, high carton breakage, etc. Therefore, a dual-passage ultrahigh-speed carton elevator was designed on the basis of single passage S-shaped elevator, wherein carton and conveying chain plate moved in the same direction to minimize the sliding friction between carton and the surface of rollers and chain plates. The results of application showed that carton conveying was stable and reliable, the maximum conveying capacity of elevator increased from 50 to 100 cartons/minute, the working life of chain plate prolonged from 2-3 to 5-6 years, while the proportion of cartons with the said defects decreased from 5%-7% to less than 0.5%.