2-fluoro-5-bromonitrobenzene was prepared from 2-fluoronitrobenzene using the solvent acetic acid (CH3COOH) instead of sulfuric acid or 2-fluoro-5-bromonitrobenzene was prepared from 2-fluoronitrobenzene using the solvent acetic acid (CH3COOH) instead of sulfuric acid or boron trifluoride, using N-bromosuccinimide (NBS) as bromide reagent. The reaction condition was mild and easy to be controlled, the target product qualitative was analysised by GC-MS and quantification was analysised by GC. The best yield(98.6%) of 2-fluoro-5-bromonitrobenzene and conversion (100%) of 2-fluoronitrobenzene were obtained under optimized conditions that n(2-fluoronitrobenzene):n(NBS) =1:1.05, the reaction temperature was 10 ℃ and the reaction time was 2 h. The repeat experiments showed that the technology had a good repeatability under above optimum conditions.