Due to the on-site supervision of pretreatment quality, it is not as easy to be judged intuitively and quickly as dyeing and finishing in the production line, and the quality semi-inspection work can usually only be a certain proportion of sampling. Moreover, some quality problems caused by poor pretreatment will be intertwined with the quality of dyeing, which makes the search and analysis of the reasons particularly complicated. Some of these defects are difficult to repair, and the repair cost is high, not to mention the more serious consequences caused by irretrievability after the fiber is damaged.