A spiro compound is a polycyclic compound in which two monocyclic rings share one carbon atom; the shared carbon atom is called a spiro atom. Spiro compounds have rigid structures, stable structures, and have special properties that general organic compounds do not possess, such as anomeric effect, spiro conjugation and spiro hyperconjugation. Compared with the monocyclic structure or the planar aromatic structure, the spiro structure has a larger three-dimensional structure; the heterocyclic spiro structure is also regarded as the biological isostere of some groups, which can change the drug to a certain extent. The water solubility, lipophilicity, dominant conformation and ADMET properties of the molecule make the optimized lead molecule easier to drug. Therefore, spiro compounds occupy a very important position in drug development.