The invention relates to a recycling method for waste sulfuric acid of a dye intermediate product, which comprises the following steps of: recovering waste sulfuric acid with a mass fraction of 40+ / -2%, settling, filtering, dewatering and concentrating, then oxidizing with an oxidant (oxyful or ozone) at 80-200 DEG C to obtain colorless transparent sulfuric acid, removing exhaust gases generated during the oxidation process under negative pressure, cooling to room temperature, storing, and directly using for producing an inorganic fertilizer, a sulfate, or a water treatment agent; or mixing the oxidized sulfuric acid with fuming sulfuric acid or sulfur trioxide to obtain 98wt% sulfuric acid, storing, and reusing for synthesizing a dye intermediate product or producing a sulfate. The waste sulfuric acid is acquired by oxidizing 1,4-diamino-2,3-dicyano anthraquinone as a raw material with sulfuric acid, then hydrolyzing to obtain a dye intermediate product namely 1,4-diaminoanthraquinone-2,3-dicarboxyl imine and hydrolyzing the dye intermediate product. The recycling method is simple and practical, the recovery rate of the waste sulfuric acid of the dye intermediates is up to 96.9%, and the recovered sulfuric acid can be used as fresh industrial sulfuric acid.