Abstract: Objective: To systematically review the effects of aerobic exercise on cognitive function in patients with Alzheimer's disease(AD), and to explore its underlying mechanisms and individual differences in intervention efficacy. Methods: Following PRISMA guidelines, we searched multiple databases from inception to September 2025 including PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang Data, and VIP Database. Randomized controlled trials(RCTs) were screened according to the inclusion and exclusion criteria, the Cochrane Risk of Bias Tool was used to assess the quality of included literature, and a qualitative analysis of the results was performed. Results: Twelve RCTs involving 1, 217 patients were included. Aerobic exercise demonstrated an overall positive trend on cognitive function in patients with AD, particularly for those with mild AD in domains of global cognition, executive function and memory. Potential mechanisms included enhanced neuroplasticity and neurogenesis, improved cerebral energy metabolism and vascular function, reduced neuroinflammation and oxidative stress. However, intervention effects were heterogeneous, influenced by disease stage, baseline fitness, genetics, exercise parameters, and methodological variations. Conclusion: Aerobic exercise appears to be a safe and feasible non-pharmacological intervention for AD patients, though efficacy varies. Future research should adopt more rigorous designs, utilize comprehensive cognitive assessment tools and biomarkers, and develop personalized exercise prescriptions based on patient characteristics to achieve precise intervention.