The invention discloses a traditional Chinese medicinal composition for treating prostatitis and a preparation method of the traditional Chinese medicinal composition, belonging to the field of modernization of the Chinese traditional medicine. The traditional Chinese medicinal composition is prepared from the following medicinal materials in parts by weight: 174 parts of rhizoma alismatis, 348 parts of herba patriniae, 174 parts of honeysuckle, 174 parts of moutan bark, 348 parts of herba hedyotis, 174 parts of radix paeoniae rubra, 174 parts of herb of hairyvein agrimonia, 174 parts of rhizoma coptidis, and 174 parts of cortex phellodendri. The traditional Chinese medicinal composition has the advantage that on the basis of the function of treating urinary tract infection, the novel main functions of the traditional Chinese medicinal composition are found, and thus the traditional Chinese medicinal composition has obvious economic and social benefits.