The invention relates to a 
bromfenac sodium preparation method. The preparation method comprises specific steps as follows: indole reacts under the action of DMSO (dimethylsulfoxide) to produce 3-bromoindole; 3-bromoindole is added to 2-methoxyethanol, acid is added for 
hydrolysis, and 2-indolinone is obtained; 
boron trichloride is added to methylbenzene, a methylbenzene 
mixed solution of p-bromobenzonitrile and 2-indolinone is added dropwise, aluminum 
chloride is then added, acid is added, a reaction is performed, and 7-(4-bromobenzoyl)-1,3-dihydro-indol-2-one is obtained; 
hydrolysis is performed with an alkaline solution, acid is added for 
neutralization, and bromfenac is obtained; 
ethanol is added to bromfenac, bromfenac and a 
sodium hydroxide solution form salt, the salt is cooled and subjected to recrystallization, and 
bromfenac sodium is obtained. Compared with the prior art, the synthetic 
route is short, high-purity 
bromfenac sodium can be prepared, the quality meets the latest standards of 
pharmacopoeia, industrial production is facilitated, and the method can provide powerful guarantee for industrial production of bromfenac 
sodium and intermediates of bromfenac 
sodium.