Luokou machines are widely used in cotton processing operations in the textile industry. The ballast cleaner can remove impurities in brocade flowers and loose cotton lint, and roll them into pieces, which is easy to use. The quality of the Luokou machine is reflected in the various quality indicators and falling objects of the product, including the number of impurities and defects in the semi-finished product, the content of short fibers, and the number of spinnable fibers contained in the falling objects. The Luokou machine can adopt free blow, less use of gripping blow, air-flow opening and impurity removal methods, to avoid fiber damage and impurity fragmentation, and reduce yarn defects caused by this reason.