Extraction and separation method of syringin

The invention relates to a method for extracting and separating ligustrin, which is to extract the ligustrin by the decoction method through crushing of excrementum passeris (Syringa oblata Lindl.var. alba Hort.ex Rehd.) branches. A ligustrin extract is eluted by 20 to 60 percent alcohol solution through an XDA-1 or AB-8 macroporous absorption resin column, and undergoes chromatographic separation through a silica gel column, and then ligustrin crystals with the purity over 97 percent can be obtained. The method comprises the following techniques: extraction of the ligustrin from the excrementum passeris, separation of macroporous resins and the silica gel column, crystallization and so on. The method has the advantages of low cost, simple and convenient operation, convenient industrialized production and so on. Both the stability and the reproducibility of the techniques are good; the purity of products obtained is more than 97 percent; and the method is suitable for extraction in mass production.