Abstract：More than 99.5% purity of medicine and liquid crystal intermediate of 4-bromo-2-fluorobiphenyl was synthesized via Suzuki coupling reaction with phenyl boric acid and 2-fluoro-4-bromo-iodobenzene as starting materials.The target compound was characterized by 1HNMR、IR and GC-MS. The generation cause of the by-product of boric acid self-coupling and terphenyl by-product was investigated, and the generation mechanism of by-products was speculated.