Vascular dementia may be the one of the main causes of early-onset cognitive impairment. Subcortical vascular cognitive impairment (SVCI) is the main subgroup of vascular dementia, but there is still little attention on early-onset SVCI. This paper analyzes the epidemiology, risk factors, clinical and imaging characteristics, differential diagnosis and treatment of early-onset SVCI, aiming to improve the clinicians’ understanding of early-onset SVCI, and enhance their recognition of super-early symptoms of early-onset SVCI.