Abstract: Traditional belt tobacco sorting device cannot reject heavy foreign matter effectively,a sorting system incorporating vertical pneumatic separation and spectral sorting technology was designed.The system was mainly composed of a vibrating conveyor,a pneumatic separating chamber,vertical pneumatic conveying duct,spectral detecting and rejecting unit,material-air separation device.Visible light and near infrared multispectral image processing was adopted to identify foreign matter and greenish strips.An open type detection channel with balanced airflow was designed to improve image clarity.Via the classification model developed from the spectral characteristics of strips together with the rejection protection algorithm based on token bucket,the classification and rejection of heavy and light foreign matters were achieved.A total of 150 foreign matters,light or heavy,were uniformly mixed into the blended strips of brand "Huangguoshu(soft 02)" to validate the separation performance and rejection rate of the system.The results showed that:1) The moisture,fines and dust contents in strips and the percentage of large and middle size strips were not affected by pneumatic conveying basically.2) With the total foreign matter rejection rate of 89%,the rejection rates of the system for heavy and light foreign matters were more than 96% and 85%,respectively.3) The designed open detection channel demanded less cleaning work.The system combined pneumatic separation with spectral sorting,it promoted the rejection rate for foreign matters.