To study the antioxidant activity and its structural characteristics of albumin from Longli 1 quinoa seeds, quinoa albumin as raw material, the antioxidant activity and structural changes of quinoa albumin during in vitro simulated digestion were analyzed by Fourier transform infrared spectroscopy and scanning electron microscope. The results showed that the degree of hydrolysis of quinoa albumin and the release of free amino acids increased significantly with the digestion of pepsin and trypsin, reaching 39.60% and 45.46mg/L respectively at the end of simulated digestion. After simulated gastrointestinal digestion, DPPH· and ABTS⁺· scavenging rate, total reducing power, Fe²⁺ chelation rate and Cu²⁺ chelation rate of albumin digestion products were 58.43%, 79.51%, 0.280,66.84% and 15.74%, respectively, which were 34.85%, 68.62%, 0.179,54.52% and 7.76% higher than those of undigested albumin. In the whole process of simulated digestion, the content of β-angle increased significantly, while the content of α-helix and random coil decreased first and then increased with the passage of digestion time. The content of β-fold increased first and then decreased. Scanning electron microscope observation showed that after pepsin hydrolysis, the digested particles become significantly smaller and disorderly arranged in a dense structure. The surface area and the pore size of digested particles increased. The research results were aimed to provide a basis for the further utilization of quinoa albumin of Longli 1 quinoa seeds.