The invention provides a feed additive for Small-tailed Han sheep, a preparation process and a use method thereof. The feed additive includes the following raw materials in mass percentages: 15-20% of lemongrass extract, 12-14% of Cordyceps flower extract, Houttuynia cordata extract Selenium-enriched yeast powder 20-25%, broken wall selenium-enriched yeast powder 5-30%, broken bee pollen 5-10%, β-sitosterol 1-2%, rumenin 0.1-0.2%, urea phosphate 10-15%, sulfuric acid Copper calcium 0.1‑0.3%, chromium picolinate 0.4‑0.5%, glycine complexed iron 0.4‑1%, rumen-passed methionine 3‑6%, rumen lysine 3‑6%. The added amount of the feed additive in the small-tailed Han sheep concentrated feed and roughage is 300-800g / t and 200-500g / t respectively. The feed additive of the present invention can stimulate the small-tailed Han sheep to eat food, promote rumination, invigorate the stomach, eliminate gas, digest and absorb, effectively reduce the incidence of rumen flatulence, increase the feed remuneration rate, improve the body immunity of the small-tailed Han sheep, and effectively reduce the incidence of sheep disease incidence.