TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method comprises (1) performing oximation reaction by adding dehydropregnenolone acetate, sodium acetate and absolute ethanol in a ratio of 1: (1.3-1.4): (2-4.5) to a reaction tank, cooling to 40 plus minus 5 degrees C, adding water (4 times), separating, centrifuging, and drying to obtain a dehydropregnenolone acetate oxime; (ii) performing Beckmann rearrangement hydrolysis reaction by adding dehydropregnenolone acetate oxime, trichloromethane, phosphorus pentoxide, hydrochloric acid and water in a ratio of 1: (6.1-6.3): (0.85-0.95): (0.58-0.75): (6.3-6.8), heating to 60 plus minus 2 degrees C, reacting for 4 hours, cooling to 5-7 degrees C, dropping hydrochloric acid aqueous solution, washing with water, concentrating, separating, centrifuging to obtain dehydroepiandrosterone acetate; and (iii) performing hydrolysis reaction by adding crude product of dehydroepiandrosterone acetate, carbinol, potassium carbonate, hydrochloric acid, methanol and activated carbon in the ratio of 1: (7.4-7.8): (0.42-0.48): (0.35-0.37): (5.3-5.7): (0.43-0.47), refluxing dehydroepiandrosterone acetate, carbinol and potassium carbonate for 1.5 hours, cooling, adjusting the pH value to 6-8 by adding hydrochloric acid, adding activated carbon and refluxing for 30 minutes, filtering, concentrating, cooling to 0-5 degrees C, centrifuging and drying to obtain the dehydroepiandrosterone product; or performing oximation reaction by adding dehydropregnenolone acetate, sodium acetate and absolute ethanol in a ratio of 1: 1.35: (2-4.2) to a reaction tank, cooling to 40 plus minus 5 degrees C, adding water (4 times), separating, centrifuging, and drying to obtain dehydropregnenolone acetate oxime; (ii) performing Beckmann rearrangement hydrolysis reaction by adding dehydropregnenolone acetate oxime, trichloromethane, phosphorus pentoxide, hydrochloric acid and water in a ratio of 1: 6.2: 0.9: 0.6: 6.5, heating to 60 plus minus 2 degrees C, reacting for 4 hours, cooling to 5-7 degrees C, dropping hydrochloric acid aqueous solution, washing with water, concentrating, separating, centrifuging to obtain dehydroepiandrosterone acetate; and (iii) performing hydrolysis reaction by adding crude product of dehydroepiandrosterone acetate, carbinol, potassium carbonate, hydrochloric acid, methanol and activated carbon in the ratio of 1:7.6:0.46:0.36:5.5: 0.45, refluxing dehydroepiandrosterone acetate, carbinol and potassium carbonate for 1.5 hours, cooling, adjusting the pH value to 6-8 by adding hydrochloric acid, adding activated carbon and refluxing for 30 minutes, filtering, concentrating, cooling to 0-5 degrees C, centrifuging and drying to obtain dehydroepiandrosterone product.