Add the O-benzylacetoxime to a mixed solution of 17 g of methanol and 200 g of a 38% mass concentration hydrochloric acid solution; react for 210 minutes at a temperature of 36°C and a stirring speed of 90 rpm; then distill under reduced pressure at a temperature of 65°C until a solid precipitate out, and cool to room temperature. The solid was washed with petroleum ether (100mL×3) and dried under vacuum at 80°C for 8 hours to obtain 95.18g of the target product O-Benzylhydroxylamine hydrochloride, with a purity of 99.87%; the yield is 98.72%.