The invention provides a medicament containing gnetales for treating bronchitis and a preparation method thereof. The medicament contains gnetales, plaster, forsythia, scutellaria, cortex mori radicis, bitter almond, hogfennel root, tuber pinellia, and the like. The medicament composition combines various medicines to dissolve phlegm and relieve cough when phlegm heat in lung is removed, close canopy of lung qi is relieved, and the loss function is in a normal state. Research shows that the medicament has good effects for treating bronchitis in different aspects of relieving cough, removing phlegm and asthma and resisting inflammatory, and the like.