Objective: A novel electrochemical sensor with high sensitivity was developed for the quantitative analysis of rutin in tartary buckwheat. Methods: A layer of titanium dioxide was loaded on the surface of ferric oxide nano materials (Fe₃O₄) to prepare core-shell Fe₃O₄@titanium dioxide (Fe₃O₄@TiO₂) nano composites, and nano gold (Au) was loaded on its surface for preparing a new type of Fe₃O₄@TiO₂@Au nanocomposites. Then an electrochemical sensor was constructed for quantitative analysis of rutin. The optimal working conditions of the sensor were determined by electrochemical characterizing of nano materials, rutin and optimizing, buffer pH, enrichment time, enrichment potential and other conditions. Results: Fe₃O₄@TiO₂@Au had good adsorption and conductivity, which could effectively improve the sensitivity of the sensor. Rutin concentration and its corresponding oxidation peak current show linear relationship in the concentration range of 0.02～20 μmol/L and 20～200 μmol/L, respectively. The detection limit (S/N=3) was 0.006 4 μmol/L, and the linear range was wide and detection limit was low. It is obviously better than other electrochemical sensors, and the sensor prepared had good repeatability, stability and good anti-interference ability to common co-existing objects. Conclusion: The prepared sensor had the advantages of simple operation, low cost and the potential of recycling of nanocomposites, which provides a more effective method for rapid quantitative analysis of rutin.