NOVELTY - Synthesis of 16- alpha -hydroxy sterane involves reacting prednisone, alkaline organic solvent and acetone to obtain sterane-containing medium body, which is reacted with oxidizing agent, organic weak alkaline retarding agent and acetone to obtain another sterane-containing medium body, which is reacted with organic solvent and semicarbazide hydrochloride. The resulting sterane-containing medium body is reacted with organic solvent, potassium borohydride and acetate acid, added to three-phase solvent reaction bottle and to multi-phase solvent to give 16- alpha -hydroxy sterane.    USE - Method for synthesizing 16- alpha -hydroxy sterane (claimed).    ADVANTAGE - The method uses prednisone as the raw material and organic weak alkaline as the retarding agent to suppress the oxidizing speed of potassium permanganate for the reaction material. It performs refining by multi-phase separating crystallizing technology. It has simple operation, warm reaction condition, feasible raw material, low cost and little environment pollution.    DETAILED DESCRIPTION - Synthesis of 16- alpha -hydroxy sterane involves:    (A) (a) adding a prednisone, alkaline organic solvent, and acetone to a reaction bottle gradually, performing temperature-maintaining reaction below 0 degrees C, performing ice-water elutriation after the plate layer analysis reaction is completed, standing the solution over night, filtering, washing, drying and recrystallizing to obtain an sterane-containing medium body of formula (I);    (B) (b) adding the medium body (I), oxidizing agent, organic weak alkaline retarding agent and acetone to the reaction bottle gradually, reacting at low temperature, adding the sulfite after the plate layer analysis reaction is completed, filtering, reducing the pressure, concentrating, cooling, filtering and drying the material to obtain sterane-containing medium body of formula (II);    (C) (c) adding the medium body (II), organic solvent, semicarbazide hydrochloride to the reaction bottle gradually, reacting at room temperature, performing ice-water elutriation after the plate layer analysis reaction is finished, standing the solution over night, filtering and drying the solution to obtain an sterane-containing medium body of formula (III);    (D) (d) adding the medium body (II) to the organic solvent, stirring and dissolving the material, adding the reducing agent of potassium borohydride, reacting at room temperature, adding the acetate acid to perform neutralizing after the plate layer analysis reaction is over, reducing the pressure, concentrating, filtering and drying to obtain an sterane-containing medium body of formula (IV);    (E) (e) adding the medium body (IV) to the three-phase solvent reaction bottle, stirring and dissolving the material, adding the nitrite solution, separating the water removing layer after the plate layer analysis reaction is over, reducing the pressure, and concentrating the solution to obtained crude product of 16- alpha -hydroxy sterane;and    (F) (f) adding the crude product of 16- alpha -hydroxy sterane to the multi-phase solvent to be dissolved, adding the water gradually until the whole system is muddy, reducing the temperature slowly until many solid materials are separated, standing the solution over night, filtering and drying the material to obtain the fined product of the 16- alpha -hydroxy sterane.