Method for extracting and purifying total flavonoids of oxytropis myriophyllum

The invention discloses a method for extracting and purifying total flavonoids of oxytropis myriophylla, which comprises the following steps: drying oxytropis myriophylla serving as a raw material until the water content is less than 8%, crushing, sieving, adding 70% ethanol aqueous solution, carrying out ultrasonic-microwave synergistic extraction and centrifugation to obtain supernate, recovering ethanol from the supernate until no alcohol smell exists, and filtering by using a microporous membrane to obtain filtrate; carrying out secondary chromatographic purification on the filtrate through polyamide resin, and washing with clear water to remove impurities; eluting the filtrate with 50% ethanol to obtain an eluent; and carrying out spray drying on the eluent to obtain the oxytropis myriophyllum total flavone dry extract with the content of more than 70%. According to the method, the extraction time is short, the efficiency is high, the total flavonoids of the oxytropis myriophyllum can be enriched to the