The invention provides an ostrich feed additive and a preparation method thereof and relates to the technical field of culture feed. The ostrich feed additive is mainly prepared from the following rawmaterials in parts by weight: 5 to 20 parts of Chinese angelica root, 10 to 25 parts of herba houttuyniae, 10 to 28 parts of fructus crataegi, 9 to 18 parts of radix astragali seu hedysari, 3 to 10 parts of rhizoma coptidis, 4 to 16 parts of quinoa, 5 to 20 parts of semen cucurbitae, 8 to 22 parts of wheat germ, 10 to 25 parts of rhizoma dioscoreae, 10 to 25 parts of black soybean, 3 to 10 partsof stone-like omphalia, 5 to 10 parts of herba artemisiae annuae, 6 to 12 parts of pericarpium granati and 8 to 15 parts of diatomite. The feed additive provided by the invention has the effects of promoting and enhancing metabolic capability and absorption capability of ostriches and improving the growth and development speeds of the ostriches; meanwhile, the feed additive also can be used for enhancing the immunity of the ostriches and reducing the illness possibility of the ostriches is reduced. The blood circulation is promoted through dietary fibers and the digestion and absorption of nutrient components in the ostriches are accelerated; the loss of the nutrient components is reduced and the effect of improving the growth speed of the ostriches is realized.