The invention discloses a method for synthesizing 3-hydroxy biphenyl, which is characterized by comprising the following steps of: under the protection of inert gas or N2 gas, using THF as a solvent,reacting bromoanisole with magnesium scraps to obtain a Grignard reagent; reacting Grignard reagent with bromobenzene in the presence of a catalyst dpppNiCl2, adding an acid solution for quenching reaction, layering, extracting water phase, separating liquid, combining the obtained organic phases, washing, drying, concentrating, and distilling to obtain an intermediate 3-methoxybiphenyl; adding the 3-methoxybiphenyl into glacial acetic acid, adding a 48% HBr solution, heating, refluxing, aging, cooling, extracting and separating, mixing the obtained organic phases, washing, drying, concentrating, and recrystallizing toluene to obtain the 3-hydroxy biphenyl. The method has the advantages of convenient operation, easy control of reaction and simple requirement on reaction equipment, the whole process is suitable for industrial production, and the GC purity of the prepared 3-hydroxy biphenyl can reach more than 99%, and the total yield is more than 60%.