There is no “best and fastest” expectorant method for baby phlegm, first of all, we still need to look at the specific cause of the disease, according to the cause of the treatment, the common treatment methods for the cause of the treatment, for the symptoms of coughing and so on. 1. Treatment for the cause: (1) Upper respiratory tract infection: If it is caused by viruses, generally no special medication is needed. If it is combined with bacterial infection, antibacterial drugs such as cefixime and amoxicillin should be used; if it is caused by influenza virus, antiviral drugs such as oseltamivir can be applied. (2) Pneumonia: For Streptococcus pneumoniae infection pneumonia, parents can follow the doctor’s instructions to the child oral amoxicillin capsules, amoxicillin clavulanate potassium and other penicillin antibiotics. If it is Mycoplasma pneumoniae pneumonia, patients can take oral erythromycin capsules, azithromycin tablets and other macrolide antibiotics. 2. Symptomatic treatment: (1) Nebulized inhalation: Nebulized inhalation can effectively moisten the airway, dilute sputum and thus promote sputum discharge. Saline nebulizer can be used only, or other drugs can be added under the guidance of the doctor, the frequency of nebulization needs to be adjusted according to the baby’s condition. (2) Expectorant medication: Oral medication such as Ambroxol under doctor’s supervision, note that expectorant medication should not be used at the same time with cough suppressant to avoid clogging of secretion after the cough reflex is weakened. All of the above medications should be used under the guidance of a doctor to avoid self-medication.