The invention discloses a traditional Chinese medicine composition for treating lung cancer and a preparation method thereof. The traditional Chinese medicine composition comprises the following raw Chinese herbal medicines: dayflower, bjerkandera fumosa, esquirol heterostemma herb, houttuynia cordata, wild buckwheat, cayratia japonica, fructus canarli, calyx seu fructus physalis, tendril-leaved fritillary bulb, radix tinosporae, physalis angulata, oroxylum indicum, scrophularia ningpoensis, Chinese alpine rush, radix rehmanniae, cortex lycii radicis, pyrrosia lingua, polygonum cuspidatum, fructus citri, sheathstipe greenbrier tuber and root, schizaea digitata, bryozoatum, campsis grandiflora, tinospora sinensis merr, sida szechuensis, bamboo shavings, aster, flos farfarae, nux prinsepiae, fructus aristolochiae, sand badger fat, and mallard feathers. The traditional Chinese medicine composition has the effects of nourishing Yin and clearing away heat, and clearing away toxic material and removing stasis, and is mainly used for treating Yin deficiency toxic-heat caused by lung cancer; the treatment based on syndrome differentiation can be carried out as a whole; equilibrium between yin and yang can be regulated for a patient; and the traditional Chinese medicine composition has the advantages of being fast to act, high in efficiency, accurate in treatment and high in safety, and no toxic and side effects, obviously reducing the course of treatment, inhibiting the growth of tumor, raising the tumor inhibition rate along with increase of dose, and interfering tumor cell proliferation, so as to realize the effect of preventing tumor.