Propacetamol hydrochloride is a non-steroidal antipyretic and analgesic drug. The synthesis process of its key intermediate, chloroacetic acid-(4-acetylamino)phenyl ester were improved and optimized. Acetaminophen was used as the starting material, acetone as the reaction solvent, and organic base pyridine as the acid scavenger. The chloroacetyl chloride was slowly added under stirring to carry out the acylation reaction to obtain the wet product of the intermediate chloroacetic acid-(4-acetylamino)phenyl ester. After drying, the intermediate powder was obtained. The overall process yield was over 90.0%, and the purity was over 99.0%. The synthetic process is simple to operate, has a simple post-treatment, high product purity, effectively saves raw material costs, and improves the antipyretic and analgesic production system. It is  suitable for industrial production.