Patients cough up sputum after surgery, because patients in surgery after surgery, mobility will be limited, most of the lying state, the body’s airway in the lying state, it is easy to be invaded by pathogenic microorganisms such as bacteria and viruses, which induces a large amount of sputum production. The human body will secrete a lot of mucus, viruses, bacteria and other pathogens as well as a large number of immune cells wrapped up in the sputum discharged from the body, so that the lungs of the human body to be protected, belonging to the body’s self-protection function. If the patient’s autoimmunity is weak, then pneumonia can develop without enough immune cells involved. Inflammatory pneumonia can also be induced in elderly patients. Post-operative patients can promote sputum expulsion by knocking on the back to expel sputum, applying Ambroxol orally as well as nebulized inhalation to promote the improvement of the condition.