The invention discloses compound feed for piglets and a preparation method and application thereof and belongs to the technical field of piglet feed processing. The compound feed for the piglets comprises, by mass, 60-70 parts of corn, 10-20 parts of bean pulp, 5-10 parts of extruded soybeans, 2-6 parts of steam fish meal, 1-5 parts of lactose, 1-4 parts of rice bran meal, 0.2-1.2 parts of wheat bran, 0.5-1 part of beet pulp, 0.3-1 part of rice hull powder, 0.03-0.09 part of multi-vitamin, 0.2-0.6 part of acidifying agents, 1.7-4 parts of phytase, 0.2-0.6 part of L-lysine, 0.01-0.05 part of DL-methionine, 0.01-1 part of mould inhibitors, 0.1-0.15 part of zinc oxide, 0.2-0.6 part of compound microelement, 0.5-2 parts of saccharomycete agents and the like. According to the compound feed for the piglets, the protein level of the piglets can be improved, and the digestibility and the immunity of the piglets are improved; and meanwhile, the effective digestibility of the piglets on nutrient substances such as zinc, phosphorus, the microelements, protein and amylum is improved, and pollution is reduced.