The invention relates to a compound feed capable of improving the growth speed and immunity of black goats and a preparation method thereof. The compound feed is prepared from, by weight, 55-75 parts of corn flour, 10-30 parts of soybean meal, 1-5 parts of rapeseed meal, 1-5 parts of bran, 0.2-0.8 part of salt, 0.1-0.6 part of premix, 5-20 parts of rice bran and 5-25 parts of traditional Chinese medicine residues, wherein the traditional Chinese medicine residues are astragalus membranaceus residues, or astragalus root, dendrobium stem and haw thorn residues and Epimedii Folium residues which are mixed according to a proportion, and the astragalus root, dendrobium stem and haw thorn residues are byproducts for producing astragalus root, dendrobium stem and haw thorn granules. According to the compound feed provided by the invention, the palatability of the feed is improved, the digestion and absorption of black goats on nutrients are promoted, and the growth speed is accelerated; and meanwhile, residual active ingredients of the traditional Chinese medicine residues improve the average daily gain of the black goats, the immunity of the black goats is improved, the growth performance of the black goats is improved, the live weight before slaughter, the carcass weight and the slaughter rate are improved, and the slaughter performance of the black goats is improved.