The invention discloses an all-natural drug for treating a human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and a preparation method for the all-natural drug. The all-natural drug is a compound preparation prepared through extracting effective active components from marine organisms and various animal and vegetable medicinal materials. The formulation of the all-natural drug comprises the following components in weight percentage: 10 percent of American ginseng, 10 percent of Astragalus mongholicus, 10 percent of Angelica sinensis, 10 percent of Salvia miltiorrhiza, 10 percent of radix rehmanniae, 5 percent of rheum officinale, 7 percent of goldthread root, 7 percent of Clerodendrum cyrtophyllum, 8 percent of zaocys dhumnade, 8 percent of Gekko japonicus, 7 percent of Chinese Polyphaga, 1 percent of centipede, 1 percent of sea dragon, 1 percent of sea horse and the balance marine algae. On the basis of the new theory of ZhengXue medicine originated by the first applicant of the invention, the formulation of the all-natural drug disclosed by the invention is improved through trial and error. Through pharmacological study and clinical use, the curative effect of the all-natural drug is remarkable. The all-natural drug not only can be used for effectively restraining HIV replication but also can be used for reconstructing an immune system, correcting immunodeficiency and recovering an immunologic function, and host cells infected by the HIV are effectively targeted, so that the viral load is greatly lowered to reach a level that the HIV cannot be checked out, and moreover, the viral load does return after drug withdrawal. The body function can be recovered, and the syndrome can be eliminated. Toxic and side effects do not exist. AIDS patients can be totally recovered.