Taking the stem and leaves of hemp as raw materials,the essential oil of hemp was obtained by water distillation extraction,subcritical extraction and supercritical extraction respectively.The differences and characteristics of the essential oil components obtained by different extraction methods were compared.The volatile components were identified and analyzed by gas chromatography-mass spectrometry (GC-MS),and the extracted components were identified and analyzed by NIST mass spectrometry library and manual analysis.Finally,the relative percentage contents of each component of hemp essential oil under the three different extraction methods were obtained according to the peak area normalization method.The components of essential oil obtained by the three extraction methods were significantly different.A total of 154 components were identified and 13 common components were included,with a similarity of more than 80%.Among them,89 different components were identified by water distillation extraction method,and the highest component was cannabinoid (19.69%).Sixty-two components were identified by subcritical extraction.The most abundant component was celluflexdop (17.56%).Fifty-nine species were identified by supercritical extraction.Oleic acid had the highest content (22.50%).The components and contents of essential oil extracted by the three methods were different in different degrees.The essential oil obtained by water distillation had the most kinds of components,mostly small molecular compounds such as alkanes,olefins,alcohols,aldehydes and sesquiterpenes,while subcritical method and supercritical method were similar to each other to a certain extent.They had 40 common components,mostly high boiling point compounds or macromolecular compounds such as acids,alcohols,esters and phenols,but the content difference was obvious.