In this paper, the effects of ultrasonic pretreatment on drying kinetics, bioactive components (polysaccharides, total phenols, flavonoids and antioxidant), qualitative characteristics (color index, lobetyolin syringin) microstructure Codonopsis pilosula during radio frequency vacuum (RFVD) were studied. The average rate curve showed that whole process could be divided into three stages: accele...