The invention belongs to the field of animal health-care, and in particular relates to a zinc oxide anti-diarrhea product for animals and a preparation method thereof. The core-shell structured zinc oxide clay anti-diarrhea preparation for animals is granular, the core layer of a granule is zinc oxide, the outer layer of the zinc oxide is enveloped with a clay layer, and the outer layer of the granule is enveloped with an enteric coating. The anti-diarrhea preparation is free from erosion of gastric acid and is released in fixed points in the intestinal tract. The clay can converge damaged epithelial cells in the intestinal tract, protect the intestinal tract, and substitute for antibiotics for controlling diarrhea. The dosage of the anti-diarrhea preparation is far less than the dosage of zinc oxide, thereby lowering the culturing cost and reducing zinc discharge and soil environment pollution.