With tetrabutylammonium bromide（TBAB） as a phase, benorilate was synthesized from acetyl-salicylic-acid-chloride and acetyl aminophenol.The reaction conditions ,such as molar ratio of reactants，reaction time，molar concentration of catalyst and the concentration of NaOH solution were optimized.Through the experiment, the determined best reaction conditions were the molar ratio of acetyl aminophenol and acetyl-salicylic-acid-chloride was 1.0∶1.2, the reaction temperature was 0 ~ 5℃, the reaction time was 40 minutes and the molar of tetrabutylammonium bromide molar concentrations was 3%, the concentration of NaOH solution was 5%. In the best condition, the yield of benorilate came up to 93.2%.