The onset of dementia in old age is related to various factors, and by reducing risk factors we can protect susceptible people and prevent the occurrence of dementia; we also need to make elderly people who may suffer from dementia actively seek medical treatment and get medical help in a timely manner; we need to make the whole society raise awareness of checking dementia, establish a practical whole society support system, help and guide the patients’ living caregivers to take care of dementia patients scientifically and prevent Complications. The prevention of dementia in old age should be achieved through health education for the general public, participation of the whole society, perfect social security work, guidance of professionals, and establishment of an active and effective prevention and treatment network with the following specific measures: I. Primary prevention Etiological prevention, the purpose of which is to eliminate the causes of the disease and reduce the influence of causative factors. 1.Popularize the knowledge of dementia prevention and enhance the ability of active prevention, specific measures are to carry out organized and planned health education, increase the knowledge of dementia-related knowledge of the population, and carry out monitoring of disease risk factors and grasp relevant information and dynamics. 2.Improve the awareness of self-care and self-care ability, enhance the ability to resist diseases, patients develop good living habits, quit smoking and drinking, arrange diet reasonably, strengthen nutrition, exercise scientifically, pay attention to the combination of work and rest, and ensure a healthy body and optimistic mental state. 3. Eliminate the causes of the disease, avoid or reduce the influence of risk factors, and protect the susceptible population. That is to say, people with positive family history of AD, people with head trauma and people with hypertension, diabetes, hyperlipidemia and cerebrovascular disease and people with a history of depression, long-term alcohol drinkers should be protected, health status and disease monitoring should be carried out, and medical intervention should be carried out in time. 4. Pharmacological intervention: The main history is to carry out corresponding pharmacological interventions for patients with vascular risk factors, and the use of cholinesterase inhibitors for patients with mild cognitive impairment is not yet advocated. Secondary prevention Early screening of dementia for early detection, early medical consultation, early diagnosis and early treatment. 1.Improve the ability of the population to recognize dementia at an early stage, instruct family members and relatives of the specific population to master the common early symptoms of dementia, explain the knowledge of dementia prevention, and instruct the specific population to conduct regular self-evaluation of mental status, i.e., intelligent status, in an effort to achieve early detection of dementia. 2. Patients with suspected dementia should work well with themselves and their families, go to the nearest specialized medical institution for examination in a timely manner, make a clear diagnosis at an early stage, receive systematic treatment, make regular home visits, and provide corresponding consultation services and health guidance. Tertiary prevention The purpose of clinical management and life care for patients with dementia is to enable patients to receive systematic treatment and care guidance and improve the quality of life. 1.Provide active and systematic treatment to stop or delay the progress of the disease, provide better medical conditions and recuperation environment, carry out scientific/reasonable and timely treatment, and patients and their families should actively cooperate with the treatment and care. 2.Try to maintain the patient’s ability to take care of himself/herself, so that he/she can obtain the greatest possible personal satisfaction and dignity. Specific measures are to create a good living environment, to prevent the occurrence of falls, and to communicate with the patient more often with language and emotion, so that he/she can experience the care of relatives. 3.Improve the general condition of the patient, maintain physical and mental health, improve the quality of life, actively prevent and treat complications, ensure nutrition, exercise appropriately, and pay attention to rest. 4.Enhance the caregiver’s ability to care. Improve the level of care. We should provide guidance and training to caregivers in community elderly institutions and geriatric hospitals on care, nursing, treatment and rehabilitation, carry out family education, provide emotional support to caregivers, and improve the physical and mental health of caregivers. 5. To strengthen the management of specialized hospitals and geriatric institutions to reduce the burden on families and caregivers, and to regularly check the condition of patients recovering at home and revise treatment and rehabilitation plans in a timely manner.