As one of the index of yarn quality, feather has attracted more and more attention from manufacturers and customers. More hairiness and longer yarn will reduce the strength of yarn, but also affect its feel and gloss. During weaving process, it is easy to cause undesirable consequences such as unclear opening, more broken ends and so on. Its fabric is easy to pill, and even there will be cross-section defects, seriously affecting the appearance quality of dyed fabrics. Therefore, in order to improve the quality of ring spinning yarn and fabric quality, hairiness must be controlled. So, knowing and mastering the causes of hairiness is the basis of controlling feather.