The invention relates to a preparing method for livestock and poultry acidified calcium salt glycolysis feed. The preparing method comprises the steps that starch substances are prepared into pulp and subjected to enzymolysis and saccharification, then a lactic acid producing strain is inoculated for fermentation, calcium hydroxide is fed in batches for fermentation, calcium lactate fermentation liquor including the thalli and lactic acid is obtained, solid-liquid separation and concentration are carried out, and then a thallus acid residue wet base and concentrated calcium lactate liquor containing lactic acid are obtained; after starch substances are prepared into pulp and subjected to enzymolysis and saccharification, a citric acid producing strain is inoculated for fermentation, solid-liquid separation and concentration are carried out, and then a citric acid residue wet base and concentrated citric acid liquor are obtained; one or more of a sugar residue wet base, the thallus acid residue wet base and the citric acid residue wet base are mixed with feed raw materials, clean water, compound bacteria and a complex enzyme, then glycolysis is carried out, and a glycolysis residue wet base is obtained; the concentrated calcium lactate liquor, the concentrated citric acid liquor and the glycolysis residue wet base are mixed, and the livestock and poultry acidified calcium salt glycolysis feed is obtained. The feed prepared with the method contains rich citric acid, calcium lactate, lactic acid, small peptide, oligosaccharide and other nutritional ingredients, and has the advantages of being high in calcium absorbing rate, capable of resisting diarrhea, good in palatability and the like.