Mild cognitive impairment is an intermediate group between normal aging and dementia, where patients have memory impairment or other cognitive abnormalities, but have not reached the severity of dementia and the condition has less impact on daily life. Mild cognitive impairment is prevalent in older adults, with a prevalence of about 16% to 20% among those over 65 years of age. Mild cognitive impairment is a high-risk group for dementia, and early detection, diagnosis and treatment can delay the occurrence or development of dementia and reduce the onset of dementia. The introduction of mild cognitive impairment greatly advances the diagnosis and treatment of dementia and reflects the new concept of early prevention and early intervention of dementia, which has important clinical and social significance.