Pediatric respiratory phlegm sound, first of all, you can use the expectorant drugs, such as ambroxol oral solution, etc., drink a lot of water, and then improve the blood routine, C-reactive protein, viral nucleic acid test, mycoplasma antibody and other related examinations. The pathogenic microorganisms that can cause coughing and phlegm in the throat include bacteria, viruses, and atypical pathogens. If the patient’s mycoplasma antibody has been elevated more than four times in the recent past, then it is considered to be a mycoplasma infection, which can be clinically treated with azithromycin and erythromycin, which are macrolides. If the patient has elevated leukocytes, C-reactive protein, calcitoninogen, this is considered to be a bacterial infection, need to use cefixime, amoxicillin, azithromycin and other related antibiotics for treatment. If the patient presents with a positive viral nucleic acid test, the use of purgative, antiviral drugs, or symptomatic treatment.