For reducing the amount of over-dried cut tobacco during start and finish of drying operation and improving the control precision of moisture content in output cut tobacco, the means for controlling over-dried cut tobacco was improved with PID control technology. An automatic water replenishing device was equipped at the entrance of HT at the upstream of the dryer and the relevant control program was modified, the working temperature at the beginning of a drying batch was automatically revised and the relationship between the moisture content in input tobacco and working temperature was obtained, replenishing water was introduced as well at the output end of the dryer to further reduce the amount of over-dried cut tobacco. The results of application showed that after improvement, the amount of over-dried cut tobacco reduced from 27.5 to 3.54 kg during start of a drying operation and from 21.9 to 5.53 kg during finish of a drying operation. The average amount of over-dried cut tobacco during start and finish of a drying operation decreased from 70 to 7.62 kg,while cut tobacco yield increased from 97.4% to 98.7%. The sensory quality of cigarette was improved, and the labor intensity of operator was reduced.