The oral liquid is prepared from ginseng, poria cocos, radix glycyrrhizae preparata, radix glehniae, rhizoma phragmitis, semen armeniacae amarae, folium perillae, platycodon grandiflorum, fructus arctii, rhizoma pinellinae praeparata, semen coicis, fructus amomi rotundus, fresh ginger, semen plantaginis and cortex magnoliae officinalis. According to the oral liquid for nourishing the lung and reducing phlegm, through comparison of test experiments of life quality self-evaluation, lung ventilation function test value, dyspnea index, six-minute walking test, traditional Chinese medicine symptom score, traditional Chinese medicine symptom score, phlegm excretion ability, weakness condition and adverse reaction occurrence condition, no adverse reaction is found. When the mode is applied to the acute exacerbation stage of the chronic obstructive pulmonary disease caused by deficiency of both qi and yin and phlegm-damp accumulation in the lung, the clinical effects of relieving asthma, resisting infection and reducing phlegm are relatively more remarkable compared with those of relieving asthma, resisting infection and reducing phlegm by only using conventional western medicines, and the combined lung-nourishing and phlegm-reducing oral liquid has obvious advantages. The life quality of a patient can be obviously improved, the dyspnea symptom is relieved, the sputum excretion capacity of the patient is improved, the diet condition and the weak state are improved, and the lung rehabilitation purpose is achieved.