Ropivacaine Hydrochloride was synthesized from piperidin-2 -carboxylic acid through acylation reaction and amidation reaction, followed by propyl reaction under ultrasonic irradiation. The effects of solvent, temperature and time under ultrasonic irradiation were investigated. The optimal conditions about the synthesis of ropivacaine hydrochloride were ascertained as follow: toluene as solvent，acylation reaction conditions were 40 ℃ for 1.5 h, propyl reaction conditions were 40 ℃ for 1 h. The total yield reached 57.8% and the objective product was characterized with melting point and 1H NMR.