Abstract: In order to further optimize the inside structure of cyclone setting and improve the quality of yarn, in this research, two cyclones with different yarn trajectory cross-sectional shape were designed and used to reduce hairiness of the ring spinning. The performance indexes of yarn such as filoplume, fracture strength and unevenness were tested, and the effects of yarn trajectory cross-sectional shape on yarn properties were analyzed in comparison with the traditional ring spinning. The results showed that the two cyclones with different yarn trajectory cross-sectional shape both had great effects on the ring yarn qualities. Due to the difference of the state of air flow in the two yarn trajectories, their effects on the yarn properties were different. Under the same spinning parameters, the properties including the 3mm and more hairiness number, breaking strength and unevenness of yarn by cyclone with circular yarn trajectory were better than the oval one.