It is impossible to tell which is better, acetylcysteine tablets or ambroxol, both are mucolytics. The two drugs have slightly different mechanisms of action. Acetylcysteine tablets have a strong mucolytic effect on phlegm, by making the glycoprotein polypeptide chains in phlegm break and thus reducing the viscosity of phlegm, so that phlegm liquefaction is easy to cough up. It is mainly used in respiratory diseases characterized by excessive mucus secretion such as bronchiectasis and chronic obstructive pulmonary disease. Ambroxol has good mucous phlegm dissolving effect and lubricating effect on the respiratory tract, which can promote the secretion of lung surface active substances, respiratory fluid secretion and cilia movement. It can promote the discharge of viscous secretion inside the respiratory tract and reduce the retention of mucus, which can significantly eliminate phlegm and improve the respiratory condition. Cough suppressants should be avoided as much as possible when using these two medicines, so as not to make it difficult to expel phlegm. It is recommended to use under the guidance of a doctor, avoid self-medication.