Industrial preparation method of polygala tenuifolia total sapogenin

The invention discloses an industrial preparation method of polygala tenuifolia total sapogenin, and belongs to the field of traditional Chinese medicine extraction. The preparation method comprises the following steps of: crushing a polygala tenuifolia medicinal material into coarse powder, carrying out reflux extraction by using an aqueous alkali solution, filtering, concentrating filtrate, carrying out reflux acidolysis on a concentrated solution by using hydrochloric acid, filtering, washing to obtain a filter cake, dissolving the filter cake by using absolute ethyl alcohol, carrying out graded water precipitation, collecting precipitate, and recrystallizing the precipitate by using absolute ethyl alcohol to obtain a polygala tenuifolia total sapogenin extract of which the contents of presenegenin and polygalic acid are greater than 90%. The method is simple to operate; separation is performed by using the difference between the acid-base property and solubility of sapogenin; a column chromatography separ