Objective To develop a method for the determination of atropine， scopolamine and anisodamine in buckwheat flour by ultra performance liquid chromatography-tandem mass spectrometry.Methods Samples were extracted by 80% acetonitrile-water， purified by Oasis PRiME HLB solid-phase extraction column. After concentration， the sample solution was separated by waters XSelect HSS T3 column. The sample was detected in positive electrospray ionization and multiple reaction monitoring mode. The matrix-matched calibrations were used for quantification.Results The linear relationships of 3 tropane alkaloids were good in the range of 1.00-50.0 ng/mL （r>0.999）. The detection limites （LOD） of 3 tropane alkaloids were lower than 0.40 μg/kg. The quantitative limits （LOQ） of 3 tropane alkaloids were lower than 1.20 μg/kg. The average recoveries of 3 tropane alkaloids in buckwheat flour were 79.7%-89.2%. The matrix effect were 62.8%-74.5%.Conclusion The method is accurate， sensitive， and suitable for the determination of 3 tropane alkaloids in buckwheat flour.