The invention provides a traditional Chinese medicine composition for treating or improving polycystic ovarian syndrome as well as a preparation method and application thereof The traditional Chinese medicine composition is prepared from the following raw materials of semen cuscutae, placenta hominis, poria cocos, radix puerariae, folium photiniae, radix salviae miltiorrhizae, rhizoma atractylodis fried with bran, prepared radix morindae officinalis, radix rehmanniae praeparata, roasted herba epimedii, spina gleditsiae, cornu cervi, radix gentianae, fried semen cassiae, cleaned fructus crataegi, rhizoma alismatis, folium nelumbinis and salted semen plantaginis. According to the traditional Chinese medicine composition as well as the preparation method and the application thereof provided by the invention, the reproductive disorder and metabolic disorder of the polycystic ovarian syndrome can be improved at the same time, and the SCFA level in intestinal tracts can be obviously improved; the levels of proinflammatory factors such as serum TNF-alpha, IL-1beta and IL-6 are reduced, so that the chronic hyporeactive inflammation is improved; the level of adiponectin receptors in fat, skeletal muscle and ovarian tissue is improved, and finally the insulin resistance of the polycystic ovarian syndrome is obviously improved; and the ovarian function of the polycystic ovarian syndrome and the maturation and development of follicles can be improved.