The invention belongs to the technical field of pharmaceutical chemicals and discloses a xanthine oxidoreductase inhibitor and a preparation method and application thereof. The xanthine oxidoreductase inhibitor is a compound with the structural formula shown in formula (I) or pharmaceutically acceptable salt or ester of the compound, wherein R1 refers to alkyl groups from C1 to C10 or naphthenic groups from C3 to C6; R2 refers to nitryl or cyano groups; R3 refers to hydrogen or methyl or trifluoromethyl. The compound can effectively inhibit the activity of xanthine oxidoreductase and can be used for preparing anti-hyperuricemia drugs or anti-gout drugs. (Please see the description for formula I.).