A 3-year-old child with cough and phlegm can be expelled by the following ways: 1. Let the child drink more warm water, which can play a role in moistening the throat and also increase the water in the bronchi, thus diluting the phlegm and promoting the discharge of phlegm in the trachea. 2. Parents can pat the child’s back to promote the discharge of phlegm in the respiratory tract through vibration. 3. If the child’s cough and phlegm symptoms are more serious, they can be treated by taking If the symptoms of cough and phlegm are more serious, they can be treated by taking cough and phlegm-suppressing drugs, taking acetylcysteine and other phlegmolytic agents for treatment, or mucus regulators such as carboxymesterol granules to relieve the symptoms. 4. For children who have difficulty taking medication, they can also be treated and relieved by nebulization, and patients should also take azithromycin granules for anti-inflammatory treatment of the tracheobronchial tubes.