Abstract: Technology of steam explosion treatment on hemp fibers was studied,and in order to research the effect of steam explosion treatment on the structure and properties of hemp fibers,the morphology,structure and properties of fibers after treatment were analyzed by using FTIR、SEM、XRD and TG.The results showed that the morphology of fibers became very clean,the cavities inside fibers shrunk,the size of pores also diminished,and the cross section gradually turned into the shape of ellipse because of swelling effect of fibers.Treated fibers also showed the characteristics of cellulose I,and the crystallinity degree and crystallite size of fibers had some decline.The dye uptake rate of hemp fibers increased from 66.62%(untreated) to 87.88%(treated).The thermal stability of fibers got improved notably,the temperature at which the fibers reached maximum degradation rate rose from 372.8℃to 395.3℃.