In this study， the fresh burdock root was treated with enzymolysis and fermentation， so as to improve the unpleasant flavor of burdock root through lactic acid bacteria fermentation on the basis of adequate dissolution of active polysaccharides. Taking polysaccharides content and flavor scores as indicators， the optimal enzymolysis conditions were determined by orthogonal experiment as follows: cellulase addition 4%， solid-liquid ratio 1∶6， temperature 55 ℃， enzymolysis time 1.5 h， ultrasonic power 200 W. Gas chromatography-mass spectrometry (GC-MS) analysis showed that aldehydes and terpene compounds， such as phenylacetaldehyde， Β-serinene， A-curcumene， are the main sources of bad flavor of burdock， which can be converted into pleasant flavor ketones and alcohols during enzymatic hydrolysis and fermentation. The results of principal component analysis and cluster analysis showed that the volatile flavor substances phenacetaldehyde， Β-serinene and A-curcumene in the liquid of burdock treated by different methods were significantly different. The combined treatment of enzymatic hydrolysis and fermentation could effectively improve the bad flavor of burdock root.