The invention discloses a formula and a preparation method of a weaned piglet antibiotic-free creep feed, and belongs to the technical field of antibiotic-free creep feeds, the weaned piglet antibiotic-free creep feed comprises the following raw materials by weight: 120-150 parts of a protein raw material, 170-190 parts of an energy raw material, and 110-130 parts of a functional antibiotic-replacing feed additive. According to the formula and the preparation method of the antibiotic-free creep feed for the weaned piglets, preferably selecting high-quality protein raw materials is very important, low-energy and moderate-protein-level are used, fibers are increased to enhance or prolong the satiety of sows, hunger stress can be reduced, and the fibers are beneficial to stabilizing the blood glucose concentration and improving the immunity of the sows. Moreover, the composition also has a stabilizing effect on insulin secretion, the weight gain is increased, endotoxin of intestinal tracts is mainly adsorbed, and the endotoxin in the body is adsorbed by lactobacillus, antibacterial peptide and plant essential oil by adding lactose, so that the health level rate of the body is increased.