Abstract: Hydroxamic acid is widely used in the flotation process of oxidized ore because of its characteristics of low dosage, strong selectivity, strong collection power and fast flotation speed. It is an important flotation collector. Aiming at the problems of high waste and low purity in the traditional esterol-hydroxylamine production process, the production technology of acyl chloro-hydroxylamine hydroxamic acid was explored. The results showed that the product purity reached 93.58% under the conditions of reaction temperature 15℃, molar ratio of hydroxylamine hydrochloride, sodium hydroxide and benzoyl chloride was 1.2:2.6:1, concentration of benzohydroxamic acid was 20% and reaction time was 6h. The synthetic method improved the product quality obviously and reduced the discharge of three wastes. The performance of the product was investigated by the flotation test of cerussite. The flotation test showed that under the condition of the same dosage of benzohydroxamic acid, the flotation effect of benzohydroxamic acid produced by acyl chloro-hydroxylamine method was similar to that of the commercially sold benzohydroxamic acid product.