This invention discloses the preparation and application of a substituted heteroaryl ketone compound. The structure of the substituted heteroaryl ketone compound is shown in Formula I, wherein the definitions of each substituent are as described in the specification and claims. The compound of this invention has MAT2A enzyme inhibitory activity and, as a MAT2A inhibitor, can be used to prepare drugs for treating or preventing diseases of MAT2A overexpression and diseases of gene deletion encoding methionine phosphorylase.