Process for preparing D-glucosamine hydrochlorate

The invention discloses a method for preparing D-glucoseamine hydrochloride, which comprises the steps as follows: (1) adding chitosan, inorganic acid and low-carbon alcohol to a reaction distillation device, and heating to a temperature of 85-110 DEG C to carry out a reaction to obtain a distillate at the tower top and a residual solution at the tower bottom; (2) filtering the residual solution to remove residue and obtain a filtrate, cooling the filtrate to separate out the solid, and carrying out solid-liquid separation to obtain coarse D-glucoseamine hydrochloride and a first mother liquid; dissolving the coarse D-glucoseamine hydrochloride into the hot water, adding activated carbon, refluxing, filtering, evaporating the filtrate to separate out the solid, dissolve the solid into ethanol, stirring, cooling, and standing to separate out crystals, filtering and drying to obtain D-glucoseamine hydrochloride. The method can remove the acetic acid generated from the reaction from the reaction system in time,