The invention belongs to the field of feeding processing and relates to broiler chicken feed and a preparation method thereof. The broiler chicken feed is prepared from the following raw materials in parts by weight: 50-60 parts of corns, 10-15 parts of soybean meal, 10-12 parts of bran, 10-12 parts of rice bran, 8-10 parts of sorghum rice, 8-10 parts of corn straws, 5-7 parts of peanut shells, 3-5 parts of fish meal, 3-5 parts of vinasse, 2-3 parts of grape seeds, 2-3 parts of allicin, 1-3 parts of pig bones, 0.3-0.5 part of isatis roots, 0.1-0.3 part of honeysuckles, 0.1-0.3 part of liquorice roots, 0.5-0.6 part of soybean oil and 0.5-0.8 part of table salt. The broiler chicken feed has balanced nutrition match, and levels of crude protein and energy in the feed are balanced so that the weight of broiler chickens meets breed standards and the quality of chicken is improved; any additive is not added in the feed so that the quality of the chicken is improved after the broiler chickens are sold, and the chicken is green and environmentally friendly, and is safe to eat; the components of the feed contain a plurality of Chinese herbal medicine components so that the immunity of the broiler chickens is enhanced, the morbidity of the broiler chickens is greatly reduced, medicines for preventing and controlling diseases of the broiler chickens are reduced, and the feeding cost of feeders is reduced.