Abstract: Dietary fiber plays an important role in regulating nutrient concentration and improving intestinal health as one of the indispensable factors in diets for livestock and poultry. In this paper, the concept and classification of dietary fiber were briefly introduced. The role of dietary fiber in alleviating intestinal diseases, such as reducing diarrhea in piglets and bacterial infection in poultry, and the mechanism of metabolic products of dietary fiber fermentation on intestinal health were summarized, providing theoretical basis for improving intestinal health and livestock and poultry production of dietary fiber.