Medicine intermediates o-aminobiphenyl synthesis method, comprises the following steps : the reaction vessel were added 3 mol o-nitrobiphenyl and 4-5 mol 2-bromotoluene, 0.5 g p-chloromethylstyrene, raised the solution temperature to 50-55 癈, refluxed for 80-110 min, reduced solution temperature to 10-16癈, standing for layered, the solution was separated and the aqueous layer was extracted with dimethylamine solution, the extract was dried with anhydrous calcium sulfate, the anhydrous calcium sulfate was removed by filtration, after recovering dimethylamine, the remaining solution was distilled under reduced pressure to collect 110-120癈, washed with sodium bromide solution, washed with methylene chloride solution, washed with trifluoroacetic acid solution, dehydrated with dehydrating agent to obtain o-amino biphenyl.