The invention provides a quantitative characterization method for a sulfur corrosion degree in transformer oil. The quantitative characterization method comprises the steps: performing test pretreatment, carrying out an aging test, removing impurities on the surface of sheet copper, correcting oxidation reaction effects, calculating a sulfur corrosion rate, and the like. By utilizing a calculationformula of a sulfur corrosion rate Vs, namely mass of sheet copper reacting with active sulfur in unit area and unit time, quantitative characterization of the sulfur corrosion degree in the transformer oil is realized. The method has a test parameter which is the mass of the sheet copper, does not involve detection of sulfides, is irrelevant to a specific corrosive sulfur component in the oil and can be used for characterizing the corrosion degree during coexistence of multiple sulfides. In actual application, the method is capable of realizing quantitative evaluation of the corrosion degreeof a copper conductor by only measuring the mass of the sheet copper before and after the aging test. The method is wide in application range and simple and feasible in operation, is not interfered by subjective factors and has high actual application significance.