Abstract: For promoting the working efficiency of YB55 overwrapper in packing cigarette packets of special size, an automatic cigarette packet collating and conveying device was designed, which was mainly composed of a servo motor, a two-stage speed reducer, a planetary gear transmission mechanism and two cigarette packet pushers. A PLC-controlled motor drives the planetary gear mechanism and further the two reciprocating pushers. Through monitoring the status of cigarette packet stacking at the outlet of the packer, the running speed of the device is automatically switched, thereby the cigarette packets were collated and conveyed automatically. The collating and conveying device was tested on a YB55 overwrapper for cigarette brand "Yunyan (Yinxiang Yanzhuang)" in Qujing Cigarette Factory. The results showed that there was no reversed cigarette packet found, the workers in charge of packet inspection reduced by 80%, the running speed and production efficiency of the packer increased by 2 700 packets/hour and 18.1 percentage points respectively. This device provides a support for promoting the production efficiency of cigarette packer.