The invention discloses a traditional Chinese medicine pill used for treating postpartum thyroiditis and a preparation method, and belongs to the field of traditional Chinese medicine. The traditional Chinese medicine pill is prepared from, by weight, 65-80 parts of radix ophiopogonis, 61-75 parts of Chinese yam, 56-72 parts of adenophora stricta, 53-68 parts of Polygonatum sibiricum Delar., 50-65 parts of jujube, 48-62 parts of dried radix rehmanniae, 45-60 parts of fructus lycii, 42-56 parts of white paeony roots, 40-52 parts of poria cocos, 37-50 parts of radix angelica sinensis, 34-47 parts of atractylodes macrocephala, 32-45 parts of platycodon grandiflorum, 30-42 parts of glossy privet fruit, 8-40 parts of cornus pulp, 26-37 parts of radix codonopsis, 23-35 parts of semen cuscutae, 20-33 parts of radix astragali, 16-30 parts of dendrobium, 14-25 parts of coix seeds, 12-23 parts of caulis bambusae in taenian, 9-20 parts of radix glycyrrhizae, 6-15 parts of oriental stephania roots, 4-10 parts of picrorhiza and 1-5 parts of prunella vulgaris. Medicinal materials selected for the traditional Chinese medicine pill conform to the monarch, minister, assistant and guide principle, the traditional Chinese medicine pill can clear fire, nourish yin, enrich blood and tonify qi and is good in absorption effect, remarkable in treatment effect and free of toxic and side effects and clinical adverse reactions, and the clinical verification shows that the cure rate of the traditional Chinese medicine pill for postpartum thyroiditis is high.