Abstract: To reduce the amount of slivers in shreds, a multistage pneumatic sliver separator was designed. The separator is mainly composed of a pneumatic separating chamber, an infeed belt conveyor, a three-way air duct, a primary air inlet duct, a secondary air inlet duct, tobacco loosening rollers and a sliver conveyor. By combining mechanical tobacco loosening with three-stage pneumatic separation and rational setting of the air velocity in the pneumatic separator, cut tobacco was fully loosened, sliver rejection rate and the shred content in rejected slivers were well balanced. Cut tobacco for cigarette of brand "Huangguoshu (Soft 02)" was tested in Guiding Cigarette Factory, the results showed that by adopting multistage pneumatic sliver separator, sliver rejection rate reached 82%, the shred content in rejected slivers was 4.7%. Long strand proportion decreased by 4.4 percentage points, the proportions of middle and short strands increased by 4.0 percentage points and 0.5 percentage points respectively. This technology provides technical supports for improving the structure of cut tobacco and reducing tobacco consumption.