In order to investigate the main source of antioxidant activity of tartary buckwheat polypeptide crude extract,it was necessary to further isolate and purify buckwheat peptides and analyze the relationship between antioxidant activity and peptide structure by structural identification.In this study,the buckwheat polypeptide was prepared by using the waste residue of buckwheat functional extract as raw material to extract buckwheat crude protein supplemented by lactobacill plant fermentation method,and the coarse extract of buckwheat polypeptide was isolated and purified by macroporous adsorption resin,dextran gel and liquid chromatography,and the antioxidant activity was taken as the index,the components with strong antioxidant activity were screened,and the antioxidant polypeptide structure was identified by liquid chromatography-mass spectrometry.The results showed that tartary buckwheat polypeptides with different purities also had different antioxidant capacity.The ABTS and DPPH radical scavenging ability of T-3 components separated and purified by Sephadex G-15 dextran gel were the best,and the scavenging rates were 96% and 94%,respectively.The antioxidant activity of purified tartary buckwheat polypeptide was significantly higher than that of crude extract (P<0.05),but the antioxidant activity was not positively correlated with the purity of tartary buckwheat polypeptide.After further separation and purification of T-3 components by liquid chromatography,the component T-3-1 was obtained.Although the purity of Tartary buckwheat polypeptide reached 98%,the inhibition rate of DPPH and ABTS was no longer enhanced.The e inhibition rates were 89% and 90%,respectively.The amino acid sequences of the main antioxidant peptides were phenylalanine-proline-tyrosine(Phe-Pro-Tyr,FPY) and tyrosine-leucine-proline-phenylalanine(Tyr-Leu-Pro-Phe,YLPF).The results are expected to provide a theoretical basis for further development and utilization of tartary buckwheat polypeptides.