Method for preparing total salvianolic acid

The invention discloses a method for preparing total salvianolic acid. The method comprises the following steps of extracting Salvia miltiorrhiza by water-containing low-grade alcohol and extracting headspace polyamide or separating macroporous resin. The method has the advantages that the transferring rate of salvianolic acid B is high and can achieve 50-60%; the loss of active ingredients is low, the quality of the prepared product is good, the content of the total phenolic acid is equal to or greater than 80%, the content of salvianolic acid B is equal to or greater than 50%, and the therapeutic effect is obvious. The invention also discloses a preparation on pharmacy and a preparing purpose thereof.