The invention discloses a lung-clearing asthma-relieving phlegm-reducing Chinese patent drug comprising the following components in parts by weight: 10-20 affine cudweed, 10-20 geranium wilfordii, 20-40 golden buckwheat rhizome, 5-15 fructus persicae immaturus, 10-20 isatis roots, 5-15 liquorice, 5-15 radix stemonae, 5-15 shizandra berries, 10-20 scrophularia ningpoensis, 20-40 concha ostreae and10-30 fructus trichosanthis. A preparation method of the lung-clearing asthma-relieving phlegm-reducing Chinese patent drug comprises the following steps of: (1) firstly coarsely crushing the components, and then uniformly mixing; (2) finely crushing to a grain diameter of less than 5 mum, and carrying out micropowder crystallization. The lung-clearing asthma-relieving phlegm-reducing Chinese patent drug can generate the pharmacological effects of clearing lung heat, resisting bacteria and inflammation, relieving coughs, eliminating phlegm, relieving asthma, nourishing yin, moistening lung, tonifying qi, and the like through the mixed and synergetic effects of the effective components of Chinese medicinal herbs and has good effects on respiratory system diseases, i.e. bronchial asthma, acute and chronic bronchitis, pneumonia, emphysema, pleural effusion, pulmonary heart diseases, chronic pharyngolaryngitis, difficult sleeping due to night cough, and the like after being taken.