Aiming at the problem that the current time span of stem soaking machine can not meet the demand of the time span of stem returning from different raw materials, the design of the existing stem soaking machine was improved. The drainage opening is set at the feed end and the middle part of the transition trough respectively, and then the drainage opening and closing is controlled through the flap door and the cylinder, so as to adjust the moisture return time of the tobacco stalk. Under the premise of other parameter setting being unchanged, the improved stalk dipper's time span of returning moisture has been increased from 45 s to 90 s, which greatly improves the time span of returning moisture of the stalk of the stalk dipper. The field test results show that the water content stability of the improved maceration machine is increased by 32%, and the improved equipment system runs stably and the control process is safe and reliable.