The invention relates to a method for concentrating, crystallizing and recovering vitamin C mother liquor in a concentration and crystallization technology of the vitamin C mother liquor. The method comprises the following steps: performing decompression, evaporation and concentration on the vitamin C mother liquor in an evaporator, wherein the concentration condition is characterized in that the relative vacuum degree is greater than or equal to 0.092MPa, when the content ratio of 2-keto-L-gulonic acid to vitamin C in the vitamin C mother liquor is less than or equal to 1.13, concentrating the vitamin C mother liquor to vitamin C under a quasi stabilization zone under the concentration condition, concentrating the vitamin C mother liquor to 2-keto-L-gulonic acid under a quasi stabilization zone under the concentration condition; when the content ratio of 2-keto-L-gulonic acid to vitamin C in the vitamin C mother liquor is less than or equal to 1.13, adding the vitamin C mother liquor in continuous flow, concentrating to a terminal point, filtering, and recovering to obtain the vitamin C crystals. The method solves the problems that the esterification conversion reaction of the 2-keto-L-gulonic acid on industrial production of vitamin C is stable, when the content of 2-keto-L-gulonic acid in the vitamin C mother liquor is high, recovery rate through concentration and crystallization of the vitamin C mother liquor is low, and the crystallization recovery rate of the vitamin C mother liquor is influenced, and the production cost is increased.