The antioxidant activity and structural changes of kidney bean protein hydrolysates during different digestive periods were analyzed by using kidney bean protein as raw material through gastrointestinal simulation model. The results showed that the solubility and hydrolysis degree of kidney bean protein were significantly increased after digestion with gastrointestinal protease. Compared with gastric digestion， the proteolysis degree of kidney bean was increased by 120.27% and the solubility was decreased by 3.46% in gastrointestinal digestion. It was found by electrophoresis pattern and antioxidant activity analysis. After intestinal digestion， the protein subunit hydrolysis was enhanced with the continued action of trypsin， resulting in an increase in low-molecular weight peptides. The subunit bands with molecular weight <14.4 ku were significantly deepened. Compared with simulated gastric digestion， the antioxidant capacity of hydrolysates was significantly enhanced. Total antioxidant capacity， Fe reduction capacity and ABTS clearance rate were increased by 25.31%， 85.76% and 53.80%， respectively. To classify hydrolysates by ultrafiltration， which are produced by the continuous digestion of the gastrointestinal tract respectively for 0.5， 2 and 3 hours. With the prolonging of digestion time， the hydrolysates showed strong antioxidant capacity due to the increase of digestible products with molecular weight less than 10 ku. Fourier transform infrared spectroscopy (FTIR) analysis showed that the hydrolysis of pepsin unfolds the protein structure. The relatively compact β-fold in spatial structure is broken and transformed into a looser β-corner. The stable structure of kidney bean protein was restored after intestinal digestion， and the β-fold increased from 34.63% to 41.29%. The contents of sulfhydryl group， total sulfhydryl group and total sulfur-containing amino acids in gastrointestinal digestions decreased continuously with increasing degree of hydrolysis. After intestinal digestion， the content of exposed sulfhydryl group， total sulfhydryl group and total sulfur-containing amino acids decreased to (4.94±0.23) μmol/g， (6.14±0.20) μmol/g and 2.08 μg/g， respectively. SEM scanning analysis showed that flocculent aggregation occurred during hydrolysis of kidney bean protein. After simulated digestion through the intestines compared to gastric digestion. The order of the protein microstructure was increased and the surface of the digested product was fine and granular.