In order to resolve the problems that unloosening butts and long leaves tend to tangle together or twisted around machine, which results in jamming, tobacco flow interruption, and machine halt frequently, a process of pretreatment in the threshing and redrying line was designed and tested. This process changed the conception of manual or mechanical bundle loosening in threshing and redrying process, cutting off the butts of tobacco bundles directly as individual treatments. Some problems of the process of bundle loosening were resolved. The treatment of individual tobacco bundles by classification was discussed for improving purity of lamina and easing the load of previous process. The results showed that ratio of bundle loosening was above 99%, ratio of jamming breakdown and operation rate of machine were improved greatly, main quality indexes of threshing improved, and economic benefit increased.