There is no such thing as the best and fastest way to expel phlegm in infants. Infants with excessive phlegm may be affected by breastmilk or the presence of infection, which can be promoted through dietary adjustments, back patting, nebulized inhalation and anti-infection treatment. If the mother eats food that is too salty, too sweet or too oily, it may cause the infant to have excessive phlegm, in which case the mother should adjust her diet and eat more light food. Allowing the infant to drink water appropriately and performing e.g. ambroxol nebulized inhalation if necessary can promote the expulsion of phlegm. If infants are infected by pathogens, they may also have excessive phlegm. Parents can pat the child’s back and nebulized inhalation of acetylcysteine to promote phlegm expulsion. If the infection is serious, if it is a bacterial infection, anti-cephalos and cefdinir can be chosen to control the infection. Infants who have more sputum, or accompanied by cough, fever and other symptoms, it is recommended to go to the hospital in a timely manner to consult the doctor to clarify the cause, and then follow the doctor’s instructions for standardized treatment. The above drugs should be used under the guidance of a doctor.