The invention discloses a medicament for preventing and treating influenza which comprises the following raw material herbs: 10-15 g of radix astragali, 10-15 g of honeysuckle, 10-15 g of chrysanthemum, 10-15 g of aniseed, 10-15 g of fennel, 5-10 g of dried ginger, 5-10 g of basil, 5-10 g of prunella vulgaris, 5-10 g of forsythia suspense, 5-10 g of spine date seeds, and 5-10 g of eupatorium fortune. The invention also discloses a preparation method. The medicament of the invention has a unique formula, has the effect of influenza prevention by the synergistic effect of the herbs, has significant effect, and has no toxic or side effect. In addition, the preparation method of the invention is simple; white vinegar is used to fully extract effective components in the medicament; and the obtained medicament is oral liquid, is safe, convenient, reliable for administration, and has low cost.