Method for extracting lactoflavin

The invention relates to a method for extracting riboflavin, in particular to the method for extracting the riboflavin from a riboflavin fermentation broth. The invention provides the method for extracting the riboflavin from the riboflavin fermentation broth to reduce the steps for extracting the riboflavin, reduce the production cost and achieve clean production. The method has the advantages of online control of the production process, short basic time, less degradation of the riboflavin, no acid-soluble back dissolving process, no generation of waste acid, less wastewater discharge, less equipment corrosion, mother liquor reclamation, pressure reduction on sewage treatment, product recycling, and improved yield by about 5 percent.