Acetylcysteine nebulization is effective in the treatment of acute and chronic bronchitis, obstructive emphysema and other diseases caused by increased sputum secretion. The main function of acetylcysteine nebulization is to dilute sputum, promote sputum discharge by reducing the viscosity of sputum, acetylcysteine can also promote the cilia in the respiratory tract to swing, increase the secretion of the glands, and also has a more positive effect on the discharge of sputum. However, it should be noted that during the treatment period there may be skin rash, drug rash, urticaria and other adverse reactions, if in the process of nebulization suddenly appeared shortness of breath, wheezing or bronchospasm and other serious adverse reactions need to be immediately stopped nebulization treatment and treatment. Patients should follow the doctor’s instructions to apply acetylcysteine to avoid adverse reactions and delays.