Abnormal methylation of RNA m6A is an important cause of the occurrence and development of many metabolic diseases， and flavonoids have the effects of preventing metabolic diseases， but the mechanism of action is not clear. In this study， unlabeled biomolecular interaction techniques were performed to investigate the interactions between the three common flavonoids (curcumin， fisetin and galangin) and demethylase FTO， and molecular docking technique was further used to reveal the mechanism of the interactions. The effect of the interaction of flavonoids with FTO on RNA m6A demethylation was investigated using an in vitro cell model of low-grade inflammation. The results showed that curcumin， fisetin and galangin could significantly quench the fluorescence of FTO protein， and increased the resistance to protease hydrolysis and thermal stability of FTO， suggesting that all the three flavonoids can directly bind to FTO. Molecular docking results showed that these three flavonoids bound to the catalytic cavity of FTO protein， and the key amino acid binding sites included Arg96， His231， His232， Asp233， His307， and Arg322， thus potentially activating the demethylation activity of FTO. Furthermore， in vitro low-grade inflammation led to an increase in intracellular RNA m6A methylation， and the direct binding of curcumin， fisetin and galangin to FTO， inhibited the inflammation-induced increase in RNA m6A methylation， of which curcumin had the most obvious effect. The results of this study provide a theoretical basis for FTO as a novel target of flavonoids in the prevention of metabolic diseases.