Cerebral small vessel disease refers to a series of clinical, imaging, and pathological syndromes caused by various factors affecting small blood vessels in the brain. Cognitive impairment is one of the most common complications of cerebral small vessel disease. Current researches have found that cognitive impairment is related to various factors such as hypoxia. Hyperbaric oxygen therapy can achieve certain therapeutic effects by improving hypoxia. This article reviews the pathogenesis of cerebral small vessel disease, biomarkers of cerebral small vessel disease, research progress on hyperbaric oxygen therapy for cognitive impairment, and focuses on the research progress of hyperbaric oxygen therapy for mild cognitive impairment and dementia, providing more references for clinical treatment.