The invention discloses a method for preparing artemether from artemether synthetic mother liquor. The method includes: using organic solvent to dissolve solid obtained by concentrating and drying artemether synthetic mother liquor, sampling on a macroporous resin column, using acetone with the volume concentration of 20-70% for eluting, performing thin layer chromatographic detection, and fractionally collecting eluant containing alpha-artemether and eluant containing beta-artemether; and respectively recovering solvents in the eluant containing alpha-artemether and the eluant containing beta-artemether, filtering to obtain crude alpha-artemether and crude beta-artemether, using ethanol to dissolve the crude alpha-artemether and the crude beta-artemether, and adding water for crystallization to obtain alpha-artemether and beta-artemether. Compared with the prior art, the method has the advantages that the alpha-artemether and the beta-artemether are successively separated from the artemether synthetic mother liquor, filler for chromatography is cheap and simple in regeneration, and elution solvent is simple and easy to recovery; and the whole process is simple and easy to control, the production cost is low, and industrial production is easier to implement.