The invention discloses trichothecenes. The general chemical formula of the compounds is shown as the formula I. The invention further discloses a preparation method and an application of the trichothecenes. Tests prove that especially when R is H or acetyl, activity of the trichothecenes for resisting a lung cancer A549 cell strain and a cervical cancer HELA cell strain is higher and is obviouslybetter than that of cis-platinum, and therefore, the trichothecenes can be applied to preparation of anti-lung cancer and anti-cervical cancer drugs; when R in the general chemical formula is H, theactivity of the trichothecenes for resisting a gastric cancer MGC803 cell strain is higher, and the trichothecenes can be applied to preparation of anti-gastric cancer cell drugs. Besides, the preparation method is simple, industrial production is facilitated, and the trichothecenes have broad application prospect when developed into antitumor drugs.