TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step (b) uses boron trifluoride complexes as dehydrating agent to obtain (III), where molar ratio between (II) and boron trifluoride complexes is 1:1-10, preferably 1:6-6.6. The step (d) comprises: carrying out epoxidation by dissolving (IV) in a mixed solvent of dimethyl sulfoxide and tetrahydrofuran, adding an alkali and heating to 70-80 degrees C, stirring for 1 hour, then cooling to -10 degrees C to 0 degrees C, adding trimethylsulfonium iodide, reacting for 16 hours at room temperature, conducting elutriation, filtering and stoving, carrying out condensation by refluxing epoxidized (IV) with diethyl malonate for 6 hours in ethanol solution of sodium ethoxide, conducting elutriation, filtering and stoving; and carrying out decarboxylation in aqueous alkaline solution/alcohol mixed solution, stirring for 16 hours, concentrating, conducting elutriation, filtering and stoving to obtain compound (V); where molar ratio between (IV), trimethylsulfonium iodide and alkali is 1:1-5:1-5 (preferably 1:3-3.5:3-3.5), and molar ratio between epoxidized (IV), diethyl malonate and sodium ethoxide is 1:1-3:1-2 (preferably 1:2-2.3:1-1.2). The step (g) comprises performing oxidative ring-opening reaction on (VII), and then carrying out oxidation by using sodium periodate. The step (h) comprises reacting (VIII) with peroxybenzoic acid in a nonpolar solvent at 0-60 degrees C for 4-24 hours, then concentrating reacted solution, performing elutriation, filtering and stoving to obtain crude eplerenone product, and then carrying out recrystallization to obtain eplerenone product with purity of 99.5%, where molar ratio between (VIII) and peroxybenzoic acid is 1:1-5 (preferably 1:1.8-2), and the reaction temperature is 48-50 degrees C and the reaction time is 6-7 hours. Preferred Components: The boron trifluoride complex is boron trifluoride acetic acid complex. The alkali in the step (d) is sodium hydride. The step (h): The nonpolar solvent is methylene dichloride, chloroform, benzene and/or toluene; the recrystallization solvent is methylene dichloride, acetone, ethyl acetate, isopropyl acetate, ethanol, methanol and/or isopropanol, preferably methylene dichloride and isopropanol in a volume ratio of 1:3.