With the deepening of social aging, age-related cognitive dysfunction has attracted widespread attention. Aerobic exercise, as an effective means of promoting human health, has been confirmed to improve cognitive function, as well as delay the occurrence and development of neurodegenerative diseases. This review summarizes the latest research on the effects of aerobic exercise on alleviating neuroinflammation, enhancing neuroplasticity, and reducing Aβ deposits, a major pathological feature of Alzheimer’s disease, and analyzes the molecular mechanisms underlying exercise-induced improvements in cognitive function, with the aim of providing a theoretical basis for the application of exercise interventions in the prevention and treatment of age-related cognitive dysfunction.