The invention discloses a preparation method of 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride. The method includes the reactions of: (1) chlorination reaction: taking phthalic anhydride as the rawmaterial, adding a mixed solution of sodium hypochlorite aqueous solution and sodium hydroxide aqueous solution dropwise, carrying out chlorination reaction, and adjusting the pH value to generate 4-chlorophthalic acid monosodium salt; (2) coupling and hydrolysis: carrying out coupling reaction and hydrolysis reaction on the 4-chlorophthalic acid monosodium salt in the presence of a catalyst and acocatalyst under an alkaline condition to generate 3, 3', 4, 4'-biphenyltetracarboxylic acid sodium salt, wherein the catalyst is a palladium-carbon catalyst or a nickel-palladium-carbon catalyst, and the cocatalyst is hydroxylamine sulfate or hydroxylamine hydrochloride; and (3) acidification into 3, 3', 4, 4'-biphenyltetracarboxylic acid, and then drying and dehydration, thus obtaining 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride. The method provided by the invention adopts phthalic anhydride as the raw material for reaction with sodium hypochlorite to synthesize 3, 3', 4, 4'-biphenyltetracarboxylic dianhydride, is low in production cost, avoids the use of potassium permanganate oxidation, simplifies the production process, and has small pollution, and high yield.