Disclosed is a plant antibiotics, prepared by adding each of plant fruits, seeds, kerns, peels, and shells or a mixture thereof at any weight ratio into a retort, heating to 115-150 DEG C, holding the temperature for 1-2 hours; then elevating the temperature to 200-250 DEG C, holding the temperature for 2-3 hours, then elevating the temperature to 350-450 DEG C, holding the temperature for 1-2 hours; collecting the dry distillation liquid of each period, mixing them, standing for 24-72 hours, waiting for stratification, isolating the transparent layer in the middle by siphon, which is the plant antibiotics disclosed. In the said plant antibiotics, the concentration of phenols is no lower than 0.5mg/ml, counted according to the amount of phenol; the concentration of formic acids is no lower than 1.5mg/ml, counted according to the amount of phenylformic acid; the pH value is 2-3.5 measured with an acidimeter. Disclosed plant antibiotics has application value in fields of medical sterilization, public health prevention and treatment, domestic bird diseases prevention, and foodstuff preservation and seasoning.