Abstract: In this paper,the changes of volatile components of mushroom stalks treated with twin screw extrusion were analyzed by gas chromatography-ion mobility spectrometry under different water content(20%,50%). Results showed that:A total of 35 volatile substances were detected,including alcohol,esters,aldehydes,ketones,furans and sulphur-containing compounds. After extruding with twin screw at 120℃ with 20% water,the contents of dimethyl disulfide,the main characteristic flavor component of lentinus edodes stalk,increased from 2.67% to 3.62%. When the water content was increased to 50% for twin screw extrusion,the contents of dimethyl disulfide was further increased to 6.66%. However,the effect on 1-octene-3-alcohol was not significant. A total of 11 kinds of components were determined as the main aroma components by ROAV and principal component score analysis,including 1-octene-3-alcohol,linalool,ethyl caproate,ethyl propionate and octyl aldehyde,3-methyl butyl aldehyde,heptyl aldehyde-M,isobutyl aldehyde,butyl aldehyde,2-amyl furan,dimethyl disulfide. The sensory evaluation and principal component score analysis showed that score of twin-screw extrusion under the condition of 120℃ with 20% water was higher,which could increase the release of volatile flavor component and improve the flavor.