Refining method and preparation method of bromfenac sodium sesquihydrate

The invention relates to a refining method and preparation method of bromfenac sodium sesquihydrate. Specifically, the invention provides the refining method comprising the steps: (a) regulating pH ofan aqueous solution of a compound represented by the formula 2 to pH of 2-3 with an acidity regulator, and thus obtaining a regulated aqueous solution; (b) extracting the regulated aqueous solution obtained in the step (a) with a first solvent and separating the solution to obtain an organic phase; and (c) regulating the pH value of the organic phase obtained in the step (b) by using an alkalinity regulator so as to separate out a solid, namely the bromfenac sodium sesquihydrate, from the organic phase. The method has the advantages that the alkalinity of the bromfenac sodium sesquihydrate can be accurately controlled, the purity and content of the bromfenac sodium sesquihydrate are higher than those of a recrystallization method, the recrystallization heating and cooling process is avoided, operation is simplifi