Ambroxol, also known as Mucosolvan, was once widely used in respiratory nebulization therapy, usually 15 mg/dose, and can be done twice a day. The main effect of ambroxol nebulization is to dilute sputum, unblock the airway, and relieve cough, sputum, and dyspnea. However, the ultrasound nebulization guidelines in recent years consider that amiloride is an intravenous preparation and cannot be used for nebulization. Therefore, Mucosolvan, also known as Ambroxol nebulizer, is no longer added to the nebulizer solution in major hospitals to avoid causing adverse reactions and medical disputes. Nebulized sputum-diluting drugs can be replaced with budesonide, salbutamol and other nebulized inhalation, which can also play a role in relieving cough, resolving sputum and calming asthma. So Ambroxol nebulization was once widely used in clinical practice, recently it is no longer recommended, and attention must be paid to its safety.