3-Bromo-5-hydroxybenzoic acid is a polyfunctional benzoic acid compound. Its molecular structure contains a hydroxyl group, a carboxyl group and a bromine atom, which are key to the substance’s high chemical reactivity; it can be used in various chemical reaction systems, including substitution, transposition and esterification. Furthermore, it can serve as a pharmaceutical intermediate in the preparation of active substances such as Cbl-b inhibitors.