The present invention relates to a cyclic peptide compound, and a preparation method, pharmaceutical composition and use thereof. In particular, the cyclic peptide compound of the present invention has a structure as shown by general formula (I). The compound of general formula (I), and isomers, racemates, pharmaceutically acceptable salts, crystalline hydrates, solvates or mixtures thereof have a use in the preparation of medicaments for preventing or treating mammalian diseases associated with histone deacetylase dysregulations.
