Corn protein powder, also known as corn gluten powder, consists mainly of corn protein and contains a small amount of starch and fiber. Protein in the pig gastrointestinal soluble protein and insoluble protein two states exist, insoluble protein easy and other macromolecule organic matter or trace elements combined, not easy to be absorbed and used by animals, almost all of the animals excreted from the body, is the composition of fecal dry matter components. Starch contains resistant starch and chronic starch, resistant starch in the digestive tract is not easy to be hydrolyzed by amylase, absorption of water after increased viscosity, affecting the peristaltic of the food, affecting the digestion and absorption of nutrients. The fiber content in corn protein powder is made up of NSP and tyrin. The content, type and structure of NSP affect the digestion and absorption of daily grain to some extent, and also affect the utilization and excretion of nitrogen.