6 months old baby with phlegm should be given treatment according to the child’s symptoms: 1, baby has phlegm, but no obvious cough, does not affect eating, playing and sleep, can give appropriate amount of more water to ensure the respiratory tract moist state, phlegm can be slowly absorbed over time, can be treated without drugs. 2, if 6 months old baby has phlegm, phlegm sound is very obvious, grunting, accompanied by cough, coughing and other symptoms, when the baby has phlegm. It is necessary to give symptomatic oral medication to relieve phlegm and cough, commonly used are Ambroxol oral solution or Ambroxol oral solution can be, also need to feed the child water appropriately and diligently. If there is a lot of phlegm, nebulized inhalation treatment can be given at home. Nebulized inhalation can act on the throat and airway, which can obviously relieve the phenomenon of phlegm and help the absorption of phlegm. If the phlegm does not decrease after a period of treatment at home, but increases instead, or if the coughing and phlegm aggravates, the child should be taken to the hospital for a detailed examination, and the medication should be further adjusted according to the actual situation of the child under the guidance of the doctor.