NOVELTY - Preparing 65% threonine using threonine fermentation broth and waste liquor involves (a) preparing threonine fermentation broth, (b) dividing fermentation broth, (c) filtering 1/3 portion of fermentation broth, and collecting permeate, and dense layer of membrane protein, (d) performing decolorization treatment, crystallizing mixture, centrifuging crystals and mother liquor, drying wet granules, and collecting mother liquor, and (e) concentrating 2/3 portion of fermentation broth, mixing e.g. membrane protein, and performing fluidized bed spray granulation.    USE - The method is useful for preparing 65% threonine (claimed).    ADVANTAGE - The method is cost-effective, and environmentally-friendly, and prepares high yield of threonine.    DETAILED DESCRIPTION - Preparing 65% threonine using threonine fermentation broth and waste liquor involves (a) preparing threonine fermentation broth, (b) dividing fermentation broth into two portions (1/3, and 2/3 portions), (c) filtering 1/3 portion of fermentation broth using a ceramic microfiltration membrane to remove retentate from filtrate, performing ultrafiltration to obtain permeate, and collecting permeate in a filtrate tank, and dense layer of membrane protein, (d) pumping the permeate into a bleaching tank, performing decolorization treatment by adding 0.5 %mass powdered activated carbon, controlling temperature of the bleaching tank at 47 degrees C for 20 minutes until pH value reaches 6, removing activated carbon using a plate and frame filter, crystallizing the mixture using a evaporative crystallizer, centrifuging the crystallized mixture, centrifuging crystals and mother liquor to obtain wet granules, drying wet granules to obtain high purity threonine, and collecting mother liquor in a storage tank, and (e) concentrating 2/3 portion of fermentation broth using a low-temperature boiler in vacuum atmosphere, mixing membrane protein, mother liquor, and organic solid filler, and performing fluidized bed spray granulation.