The invention discloses a plant essential oil capable of preventing and controlling neoschngastia gallinarum hatori. The plant essential oil is prepared from, by weight, 2-20 parts of thymol, 1-10 parts of eugenol, 1-10 parts of methyl eugenol, 0-15 parts of carvacrol, 1-20 parts of cinnamaldehyde, 0.1-2 parts of sanguinarine and 0.1-2 parts of chelerythrine. According to the characteristics of various plant essential oils, the optimal proportion for treating neoschngastia gallinarum hatori of chickens is screened out; the plant essential oil is compounded of a plurality of plant essential oils and has a very good antibacterial effect; the thymol and the cinnamaldehyde have an obvious synergistic effect in a mass ratio of 5:1, so that a medicament is safe, green and efficient and has no toxic or side effect, drug resistance, residues or incompatibility.