The invention provides a soluble powder for treating toxoplasmosis and a preparation method thereof. Being an orally taken medicine, the soluble powder contains sulfadimidine, lactic acid TMP, lincomycin hydrochloride, as well as anhydrous glucose, and can be used for treating toxoplasmosis of animals. The powder can be used for blending or can be used after adding water. The soluble powder has a low cost and a good effect, thus being suitable for industrial production.