Abstract: The structure and working principle of the carton collating mechanism for case filling and sealing machine were introduced, the matching between moving parts was analyzed and the cam was improved. By changing the structure of the elevator, the collating mechanism started running as soon as the elevator descended, and the time for cigarette cartons to reach their right positions was prolonged accordingly. After improving, the mechanism ran stably and throughput increased from 200 cartons/minute to 275 cartons/minute.