The invention belongs to the technical field of chemical industry, and particularly relates to a method for enriching cannabidiol. The method includes steps of S1, drying Cannabis sativa flower and leaf for 0.5-4 hours at 120 DEG C, and smashing until the particle size of the smashed material meets the requirement of over 50 meshes; performing carbon dioxide supercritical extraction for 1-9 hours under the conditions of 30-55 DEG C and 13-30 MPa, and recycling carbon dioxide to obtain initial extractive of Cannabis sativa flower and leaf; S2, dissolving the initial extractive of Cannabis sativa flower and leaf in ethanol or methanol, refining, filtering and removing impurities, distilling and drying the solvent for future use; S3, filling a chromatographic column with the pretreated filler, sampling by a wet method or a dry method, wherein the sampling amount is 3-15 wt%; S4, performing gradient elution or isocratic elution by one or mixture of water, methanol, ethanol, n-butyl alcohol, acetone or chloroform; collecting the dilution section with enriched cannabidiol. The method is simple in technique; content of cannabidiol is improved, and tetrahydrocannabinol content is reduced.