In this paper, citric acid was used as a carbon source L-cysteine as a modifier, and carbon quantum dots with high fluorescence yield were prepared by simple hydrothermal synthesis.The experimental analsis shows that in the presence of Fe3+, the synthesized carbon quantum dots can simultaneously detect taxifolin as a fluorescent probe and a resonance Rayleigh scattering(RRS) probe. Under the optimal experimental conditions, Fe3+ can significantly quench the fluorescence of carbon quantum dots, and RRS intensity has a certain degree of enhancement. When the taxifolin was added to the above system, the fluorescence of the quenching system was recovered, and RRS spectroscopy intensity was significantly enhanced when the three coexisted. Based on this, the article optimized the detection of taxifolin by constructing two kinds of spectroscopy methods, and finally determined RRS spectroscopy method with more sensitive detection limit and wider linear range as the experimental method for rapid detection of taxifolin. Under the optimal experimental conditions, the intensity of RRS enhancement has a good linear relationship with the concentration of taxifolin in the range of 0.9-160×10-7mol/L. The minimum detection limit is 8.6×10-9mol/L, correlation coefficient is 0.9975. And the content of the standard sample detected by the experimental method is compared with the measured value of the high performance liquid chromatography indicated by the seller, and the spiked recovery experiment of the water sample has obtained satisfactory results.