The present invention relates to the field of pharmaceutical chemistry, and particularly to a compound represented by Formula (I), a preparation method and medical use thereof. In the compound represented by Formula (I), a lactulosyl group is connected to a heteroatom of genin (G) via a glycosidic bond, wherein the genin (G) is a group formed by removing one hydrogen atom from a heteroatom of an active pharmaceutical molecule, and "" indicates that the lactulosyl group is connected to the heteroatom of the genin (G) via an α-glycosidic bond or a β-glycosidic bond. Pharmacokinetic experiments prove that the lactuloside compound according to the present invention can pass through the gastrointestinal tract of a mammal without being absorbed significantly by the gastrointestinal tract and hydrolyzed significantly by endogenous enzymes of a mammal host. Therefore, the lactuloside compound can arrive at the colon site of the mammal, and release an active drug in the colon under the action of colon flora. The lactuloside compound has a function of colon-localized drug release, and can be used for preventing or treating an intestinal disease.