NOVELTY - Preparing coumarin extract diosgenin involves grinding bean to sweet fish powder, stirring for 30 minutes at 80 degrees C in water, and extract centrifugal filter, filter residue by water, centrifuging, filtering, carrying out enzymolysis to fermented liquid, drying and dehydrating hydrolysate after filtering filter residue water washing to neutral, then drying and dehydrating, extracting: the dehydrated substance by using gasoline extraction at temperature of 75 degrees C, and recovering gasoline in extracting solution, separating our saponin crystal, and centrifuging and filtering separated crystal.    USE - For preparing coumarin extract diosgenin (claimed), used as hormone type medicine for clearing hormone of female.    ADVANTAGE - The method provides resource, to replace the traditional diosgenin (ginger), and reduces pollution. The method improves the multipurpose utility value product; wide raw material source is easy to form scale, improves the resource utilization rate, reduces cost, and releases the hormone shortage of raw materials.    DETAILED DESCRIPTION - Preparing coumarin extract diosgenin involves grinding bean to sweet fish powder, stirring for 30 minutes at 80 degrees C in water, and extract the centrifugal filter, the filter residue by water, centrifuging, filtering, repeating for three times, at last the three combined leaching liquor, condensing to a concentration of the concentrated solution is 30%, the concentrated solution naturally put for 4 days (in 2 days) so as to naturally ferment, filtering the residue after drying can be used as feed or feed additive, 2) carrying out enzymolysis to the fermented liquid. Hydrochloric acid solution with the concentration of 7 mol/L, at 135 degrees C, 0.2 MPa under the condition of carrying out acid hydrolysis for 2 hours, 3) drying and dehydrating the hydrolysate after filtering the filter residue water washing to neutral, then drying and dehydrating, 4) the dehydrated substance by using gasoline extraction at temperature of 75 degrees C, and recovering the gasoline in the extracting solution, and the concentrated solution is placed for one day, saponin crystal is separated out, and 5) centrifuging and filtering the separated crystal, drying to obtain saponin ( greater than or equal to 95%).