Bronchitis croup is considered to be caused by the relative narrowing of the airway due to bronchospasm, which may be caused by the vagus nerve excitation and release of acetylcholine acting on choline receptors and leading to bronchoconstriction. Cough expectorant and asthmatic drugs should be used, and the main drugs for cough and phlegm are compound licorice syrup and aminoglutethimide hydrochloride. The medicines for asthma calming can use aminophylline, cholinergic blockers, beta 2 agonists. In addition, if the duration of the disease is more than 10 days, there is usually a bacterial infection, and also need to use antibiotic drugs, such as macrolides or penicillin, during the treatment period must drink more water, more rest, to avoid labor, especially not to stay up all night, and after the recovery of the physical fitness, to prevent colds.