Abstract: As a solution to the frequent chain blockage in chain drive system and frequent guide wheel replacement at turning section of HCF-M tray loader, the chain drive system was upgraded. The drive motor was reversed via changing motor parameters, the main drive chains reduced by 196 links, 1.9 meters in length. While keeping the synchronous relation between driven shafts unchanged, a combined double sprocket system was designed to replace single sprocket. The new system dispensed with two reverse drive sprockets and five chain guide wheels, and decreased the cumulative error caused by chain wear. The cigarettes of brand "Baisha (Prime)" were tested in Changsha Cigarette Factory, and the results showed that the number of failures of HCF-M tray loader due to chain drive system reduced by 4.7 times within 12 months, the average maintenance time shortened by 346.5 min/machine. This technology provides a support for promoting the running stability of cigarette storing and conveying system.