Objective To investigate the correlation between brain iron content and cognitive function in patients with Alzheimer's disease （AD）， and to assess the diagnostic value of iron deposition in AD using quantitative susceptibility mapping （QSM） technology. Methods Forty-three patients with AD who visited the Second Affiliated Hospital of Xinjiang Medical University between January 2024 and December 2024， and 42 healthy controls matched for gender and age were enrolled in the study. Comprehensive clinical data were collected from all participants. All subjects underwent brain MRI scans using a Philips Ingenia CX 3.0T magnetic resonance imaging system， including both QSM and conventional cranial MRI sequences. The acquired QSM images were post-processed and normalized using the STISuite software package， and the iron content in predefined regions of interest was quantified using ITK-SNAP. All participants also underwent neuropsychological assessments. Differences in regional brain iron content between AD patients and healthy controls were analyzed and compared. Spearman’s correlation coefficient was calculated to evaluate the relationship between iron levels in the frontal cortex， basal ganglia， and hippocampus and cognitive performance. Receiver operating characteristic （ROC） curves were constructed to assess the diagnostic accuracy of iron deposition in differentiating AD patients from healthy controls. Results （1） Compared with the control group， the magnetic susceptibility values in the basal ganglia and hippocampus of the AD group showed statistically significant differences （P < 0.01）， with higher values observed in the AD group. No statistically significant difference was found in the susceptibility values of the frontal cortex between the AD group and the control group （P > 0.05）. （2） In the AD group， the susceptibility values of the left caudate nucleus and left hippocampus tail were negatively correlated with the MMSE scores （P < 0.05）. Additionally， the susceptibility values of the left caudate nucleus， left putamen， left hippocampus， and left hippocampus tail were negatively correlated with the MOCA scores （P < 0.05）. （3） The area under the curve （AUC） for diagnosing AD based on the left caudate nucleus was 0.758 （95%CI： 0.649–0.867）， for the left putamen it was 0.719 （95%CI： 0.606–0.831）， and for the left hippocampus tail it was 0.640 （95%CI： 0.518–0.763）. Conclusions （1） The iron content in certain brain regions of AD patients is elevated compared to that in healthy controls， particularly in the basal ganglia and hippocampus. （2） The iron concentration in the brains of AD patients， especially in the left caudate nucleus， left putamen， left hippocampus， and hippocampal tail， is negatively correlated with cognitive function. Higher iron levels are associated with more severe cognitive impairment， suggesting that iron accumulation may serve as a potential biomarker for assessing disease severity. （3） Iron deposition in the left caudate nucleus and left putamen demonstrates certain diagnostic value for AD and holds promise as an imaging marker for the auxiliary diagnosis of the disease.