A general QuEChERS purification method was used to establish an HPLC-MS/MS method for the determination of Bentazone and its metabolites 6-hydroxymetazone and 8-hydroxymetazone residues in rice and flour. The results showed that the calibration curves had a good linear relationship between bentazone and its metabolites in the range of 0.1 to 100.0 μg/kg, and the linear correlation coefficients (R²) were all greater than 0.995, with the limits of quantification were all 0.2 μg/kg. Methods at the levels of 0.2 μg/kg, 0.4 μg/kg and 2 μg/kg, the average recovery rates were between 89.6% and 106.9%, and the relative standard deviations were between 1.4% and 11.7% (n=6). The detection method was fast, high sensitivity, accurate and accurate, and the results are stable. It was suitable for the determination and confirmation of Bentazone and its metabolites 6-hydroxy-10-propafenone and 8-hydroxy-1-propafenone residues in rice and flour.