Abstract: The technique of high temperature degumming of hemp was researched,and the effect of temperature and concentration of alkali on the composition and structure of hemp was discussed.Scanning electron microscope(SEM),Fourier-Transform-Infrared(FT-IR) and wide angle X-ray scattering(WAXS) were used to characterize the morphology and structure of aggregating state of hemp before and after high temperature degumming.The experiment results demonstrated that after high temperature degumming the contents of hemicellulose and lignin of the hemp have reduced by 79.1% and 83.5% respectively.The crystallinity of treated hemp is raised,which is related to the treatment temperature and concentration of alkali.