Infant protein allergy clinically common is milk protein allergy, milk protein allergy has several manifestations, which can be initially judged from several aspects: 1, if the infant with dairy products, especially after drinking milk appear abdominal pain and crying, the child will not be in pain, just crying, crying without reason. There are also changes in stool characteristics, there may be blood in the stool, mucus stool, increased frequency of stool, or bloating, stomach discomfort, which are gastrointestinal symptoms; 2, some children may show recurrent eczema, red bumps after red bumps, if there are symptoms in these areas, we should initially consider milk protein allergy. This is a preliminary judgment, to confirm whether it is milk protein allergy, stop all milk protein, stop breast milk, stop milk products, feed amino acid formula alone, try to treat for a week to see how the situation is, this is a diagnostic treatment, but also a more practical and reliable treatment to confirm the diagnosis of milk protein allergy.