Ambroxol hydrochloride injection has the effect of diluting sputum, which can break the mucous fibers in sputum, thus playing the role of diluting sputum, and reducing the viscosity of sputum by inhibiting the synthesis of glycoprotein, and promoting the expulsion of sputum. It is suitable for the expectorant treatment of acute and chronic respiratory diseases caused by abnormal sputum secretion and poor sputum excretion function, such as acute attack of chronic bronchitis, wheezing bronchitis and bronchial asthma. It can be combined with antibiotic drugs, such as penicillins, cephalosporins, macrolides and quinolones, which can enhance antibiotic efficacy when used simultaneously with antibiotics. Chinese patent medicines, such as cough syrup, Chuanbei Loquat Paste, Powerful Loquat Loquat, etc., can be given to relieve cough and resolve phlegm.