The invention discloses a recovery method of mother liquor in the preparation process of glucosamine sulfate and sodium chloride double salt. The recovery method comprises the following steps: (1) recovering organic precipitants in refined mother liquor of a glucosamine hydrochloride crude product and crystallized mother liquor after salt-forming reaction of the glucosamine sulfate and sodium chloride double salt, mixing, controlling the solid content, reducing the pressure and evaporating to remove part of water; (2) adding an extracting agent to extract impurities and adding activated carbon into a water phase to decolor; (3) weighing a decoloring solution, sampling and detecting the contents of glucosamine, sulfate ions and chloride ions, and calculating the respective contents; (4) adding quantitative anhydrous sodium sulfate into the decoloring solution and performing temperature rise reaction; (5) controlling the temperature and the dripping speed, adding an organic precipitant, reducing the temperature and crystallizing, filtering and drying to obtain a glucosamine sulfate and sodium chloride double salt recovery product. The recovery method disclosed by the invention is simple in process, easy to operate, high in recovery rate and low in recovery cost; a product with relatively good crystal shape, uniform granularity, good color and luster and stable properties can be prepared; therefore, the recovery method is very suitable for industrial production.