Abstract: A special hairiness reducing nozzle was attached on a winding machine. The design and attachment of the nozzle should not change the yarn twists and strength.The mechanism of hairiness reducing of the nozzle was analyzed,which utilized an air-jet to produce the rotating air stream to perform false twisting,de-twisting and wrapping of the yarn so as to wrap the hairiness onto or twist it into the main yarn,thus reducing yarn hairiness.The position and method for attaching the nozzle were introduced.The hairiness index,hairiness appearance,twist and strength of the yarn produced by the winding machine attached with the nozzle were examined.The results indicate that the processed yarns have their hairiness index lowered,hairiness appearance improved,and the twist and strength kept unchanged,which verified the hairiness reducing effect of the nozzle.