Abstract: The present application provides a compound dry powder inhalant, comprising baicalin, ambroxol hydrochloride, L-leucine and phosphate, wherein based on a mass of the compound dry powder inhalant, L-leucine accounts for 0-50%, phosphate accounts for 15-35%, and a total mass of baicalin and ambroxol hydrochloride accounts for 15-85%, and wherein a mass ratio of baicalin to ambroxol hydrochloride is 1:0.2 to 2. The compound dry powder inhalant has a Dv90?5 ?m. The drug combination of baicalin and ambroxol hydrochloride can effectively reduce inflammation and oxidative damage in lung tissue, alleviate pulmonary edema and histopathological changes, and reduce pulmonary dysfunction and pulmonary fibrosis.