Abstract: In order to meet the large detection needs of industrial hemp flowers, leaves, stems and seeds brought by the rapid development of industrial hemp in Heilongjiang Province, the method of simultaneous determination of the cannabidiol acid（CBDA）,cannabidiol（CBD）,tetrahydrocannabinolic acid（THCA-A）and tetrahydrocannabinol（THC）by high performance liquid chromatography were established.The four cannabinoids in industrial hemp flowers and leafs, stems, seeds were extracted with 20 mL methanol-hexane solution of 90∶10（V∶V） twice by shaking, then centrifuged, and all the supernatants were collected and mixed.The extract solution was separated by a C18 chromatographic column, detected by a variable wavelength ultraviolet detector（UVD）,and quantified by matrix addition.The results showed that the four cannabidiols had a good linear relationship between 0.5-25.0 mg·L^-1,and the correlation coefficient R~2 was greater than 0.999 4.The recovery of cannabinoids were between 89.6% and 99.7%,the relative standard deviation（RSD）was ranged from 1.5% to 4.8%,and the LOQ was 0.1 mg·kg^-1.The method has the advantages of rapidness, simple operation, high sensitivity, etc.,and can meet the detection requirements of CBDA,CBD,THC and THCA in industrial hemp.