The invention relates to a Chinese medicinal additive for livestock and poultry feeds and a preparation method thereof. The additive comprises the following compositions in portion by weight: 0.8 to 1portion of angelica, 1 to 2 portions of Chinese angelica, 3 to 5 portions of gypsum, 1 to 2 portions of indigowoad root, 0.5 to 1.5 portions of skullcap, 1 to 2 portions of hawthorn fruit, 1 to 2 portions of malt, 1 to 2 portions of stored yeast, 1 to 2 portions of danshen root, 1 to 3 portions of pilose asiabell root, 1 to 3 portions of astragalus mongholicus, 0.5 to 1.5 portions of flos caryophyllata, 1 to 3 portions of anise, 0.5 to 1.5 portions of cumin, 1 to 3 portions of cassia, 1 to 2 portions of amomum globosum loureiro, 1 to 3 portions of fennel, 1 to 2 portions of drill seeds, 1 to2 portions of villous amomum fruit, 1 to 3 portions of tangerine peel, 2 to 5 portions of dried ginger, 5 to 10 portions of cypress seeds, 2 to 5 portions of mugwort leaves, 2 to 5 portions of ginkgoleaves, 1 to 3 portions of netmeg, 1 to 2 portions of white cardamom, 5 to 10 portions of maggot, 5 to 10 portions of yellow mealworm, 5 to 10 portions of earthworm, 3 to 8 portions of pricklyash peel, 40 to 60 portions of corn, and 20 to 40 portions of lucerne. The preparation method comprises the following steps: firstly, carrying out frying pre-treatment on the hawthorn fruit, the malt and thestored yeast; and then, mixing the three compositions with other compositions evenly. The additive can improve the capability of disease prevention and disease resistance of livestock and poultry, improves the meat quality of the livestock and the poultry, and has low cost.