The following are ways to improve the child’s coughing up phlegm: 1. Drink more water: Parents let the child drink warm water several times in small amounts to moisten the respiratory tract and dilute the phlegm so that it can be easily discharged with the coughing action. 2. Heat fumigation: Parents take a larger wide-mouth container, pour boiling water inside, protect the child, and let the mouth and nose do deep breathing action against the rising water vapor for about 15 minutes. The water vapor can also dilute the sticky phlegm in the respiratory tract, which can be easily discharged with the coughing action. 3.Knock on the back: Let the child sit with his back to the parent’s lap, hold it with one hand and pat the back with the other hand in the shape of a hollow fist, which will also loosen the phlegm in the respiratory tract and make it easy to cough out after the shock. 4.Medication: Under the guidance of a doctor, take cough and phlegm medicines, such as Ambroxol Hydrochloride syrup, to help improve the The symptom of coughing up phlegm without coming out.