The invention provides a feed additive for feeding rabbits. The feed additive comprises, by weight, the following raw materials: 4-7 parts of root of hairy asiabell, 8-10 parts of honeysuckle flowers,6-8 parts of apples, 1-2 parts of methionine, 1-2 parts of lysine, 10 -15 parts of glutinous rice flour, 10-15 parts of corn flour, 0.002 part of bifidobacteria and 150 parts of rice washing water. Apreparation method of the feed additive for feeding rabbits comprises the steps of crushing, fermenting, filtering and mixing. According to the invention, the root of hairy asiabell, the honeysuckleflowers, the apples and other raw materials are matched to make the feed additive contain rich nutrient elements and effective active ingredients so that the absorption of nutrient substances can be promoted, the regeneration capacity and the metabolism capacity of the body can be enhanced, and the growth and development of rabbits can be promoted. The prepared rabbit feed additive is good in quality, can meet the growth requirement of rabbits, can improve the feed intake and the weight gain rate of the rabbits, is low in morbidity and death, enhances the meat quality of the rabbits, and has strong market competitiveness.