The invention provides a crystallization method of adipic acid. The method comprises steps as follows: a crude adipic acid product is subjected to first-stage crystallization and a first-stage crystallized slurry is obtained; the first-stage crystallized slurry is subjected to first-stage thickening, first-stage dehydration and first-stage dissolution decolorization, and a first-stage product is obtained; the first-stage product is subjected to second-stage crystallization and second-stage crystallized slurry is obtained; the second-stage crystallized slurry is subjected to second-stage thickening, second-stage dehydration and second-stage dissolution decolorization, and a second-stage product is obtained; the second-stage product is subjected to third-stage crystallization and third-stage crystallization slurry is obtained; the third-stage crystallization slurry is subjected to third-stage thickening and third-stage dehydration, and adipic acid is obtained. Compared with the prior art, through three stages of crystallization, three stages of thickening and dehydration and two stages of dissolution decolorization, the transmittance, the iron content, nitrate and other key indexes of the finally obtained adipic acid are further improved, and high-quality adipic acid at chemical fiber and polyester grades is produced; besides, the process is stable, is slightly changed from the original process structure and is easy to operate.