Abstract: To solve the problem that slivers tended to jam in the conveying system in PROTOS M5 cigarette maker, a model of pipeline was developed with Solid Works software. By simulating the air flowing in the pipeline with Fluent analysis software, the pressure and air flow in the pipeline were analyzed to find out the reasons causing sliver jam. Then the device was optimized as following: instead of the bend pipe with a vibrating trough to shorten the length of conveying pipeline; having the longer slivers cut to prevent them from blocking the bend pipes; connecting sliver container to the centralized vacuum source with a straight pipe to reduce pressure loss. The results showed that: 1) The pipeline tended to be blocked when vortex flow appeared at the same cross section or the maximum curvature of pipeline, or the flow rate was zero at the maximum bend, or the pressure in pipeline dropped drastically. 2) After improvement, the pressure and air flow distributed uniformly in pipeline, the pressure loss in pipeline reduced from 452.8 to 245.5 Pa, and the blocking of pipeline was effectively avoided.