The invention discloses a traditional Chinese medicine agent for treating sleep disorder caused by circadian rhythm disorder. Active ingredients of the traditional Chinese medicine agent include cortex moutan, fructus gardenia, radix scutellariae, radix bupleuri, micalex, radix curcumae, poria cocos, radix paeoniae alba, bergamot root, rhizoma atractylodis macrocephalae, fried jujube kernel, pig-gallbladder-shaped eggplant, semen boitae, pericarpium trichosanthis, radix polygalae, rhizoma ligustici wallichii, radix angelicae sinensis, dried earthworm, ossa draconis, oyster, sandalwood resin, cortex albiziae and rhizoma nardotachyos. The invention further discloses a preparation method of the traditional Chinese medicine agent. The preparation method includes: The traditional Chinese medicine agent has the advantages of good treatment effect, little side effect, high compliance and almost zero dependence.