Nebulization refers to aerosol inhalation therapy, which is used to achieve therapeutic effects by dispersing drugs into tiny droplets through a nebulizing device and then inhaling them into the lungs, and can be used to prevent and treat obstructive airway diseases. Saline is 0.9% sodium chloride solution, used to do nebulization can moisten the respiratory tract, change the viscosity of sputum, and is conducive to the discharge of sputum. Commonly used in pneumonia, bronchitis, chronic obstructive pulmonary disease, asthma and other phlegm thick and sticky sputum is not easy to cough out of the patient’s treatment. However, the role played by saline nebulization alone is limited, often used together with other drugs, such as bronchodilators (ipratropium bromide), phlegm chemotherapy (acetylcysteine), glucocorticoids (budesonide) and so on. Patients need to be guided by their doctors to choose the right medication for their condition.