Abstract: In order to make better use of low grade tobacco, a flow extraction system for tobacco was developed. The system was mainly composed of an extraction tank, an extraction solvent recycling unit and an extraction solvent supplying unit. In the recycling unit, extraction solvent was separated from extracts. The supplying unit supplied extraction solvent to the extraction tank for flow extraction. Cut tobacco of low grade was treated by flow extraction and cylinder drying (the control) separately, the results showed that: comparing with the control, the flow extraction reduced the change rate of long strand proportion, nicotine, tar and hazard index by 1.22 percentage points, 40.37% , 33.13% and 25.67% , respectively; while increased potassium by 34.55%. After extraction, the utilization value of cut tobacco was promoted as a whole, more than 43.9 RMB yuan/kg could be saved. The system not only improves the utilization value of low grade tobacco, it is also helpful to reducing tar and harmful components.