Abstract: In KTC80 tobacco cutter with hydraulic drive system,the hydraulic oil tends to leak and pollute cut tobacco because of high working pressure. Therefore,the drive system was upgraded as following: adopting AC asynchronous servo motor and AC synchronous servo motor in the place of hydraulic system and PIV reducer to drive knife drum and band respectively; using SIEMENS S7-300C PLC to control the speed of knife drum and band,setting the width of cut tobacco at will on a touch screen; adopting pneumatic controlled right-angle crank pressure booster for tobacco compression. The application results showed that oil leakage was avoided,the error of cut stem width and the proportion of short strands reduced by 1.41 and 0.03 percentage points,respectively; while the proportion of long strands increased by 0.98 percentage points. The amount and cost of spare parts decreased,machine operation and maintenance were simpler,and the complete equipment was promoted technically.