The invention belongs to the field of traditional Chinese medicine (TCM), relates to a traditional Chinese medicine composition and a preparation method thereof, and specifically relates to a traditional Chinese medicine composition for the treatment of endometrial hyperplasia and a preparation method thereof. For overcoming the defects that existing chemotherapeutic drugs for endometrial hyperplasia are large in hepatotoxicity and poor in curative effect, the invention provides a traditional Chinese medicine composition for the treatment or prevention of endometrial hyperplasia, and the traditional Chinese medicine composition comprises the following components: 10-50 parts of herba leonuri, 10-20 parts of fructus ligustri lucidi, 5-20 parts of epimedium, 5-15 parts of cassia twig, 5-10 parts of radix achyranthis bidentatae, 5-15 parts of lotus leaves, 5-15 parts of honeysuckle, 1-10 parts of codonopsis pilosula, 5-15 parts of rhizoma anemarrhenae, 9-15 parts of caulis spatholobi, 9-15 parts of radix rehmanniae, 5-15 parts of folium artemisiae argyi, 1.5-9 parts of malaytea scurfpea fruits, 5.5-15 parts of semen cuscutae, 6-9 parts of fructus rosae laevigatae, and 10-15 parts of radix glycyrrhizae. The traditional Chinese medicine composition has a good treatment effect on the treatment or prevention of endometrial hyperplasia; and the traditional Chinese medicine composition has low drug side effects, and has significant clinical promotion value.