Like hypertension, diabetes and other chronic diseases of old age, the pathogenesis of dementia is complex, with genetic factors involved, but also closely related to environmental factors and lifestyle. Although many of the exact causative factors are still not fully understood by humans, prevention can still be achieved by avoiding some controllable and preventable risk factors. 1, regular physical examination, early prevention and treatment. The elderly should undergo regular physical examinations to keep their weight, blood pressure, blood sugar and cholesterol levels within normal limits. Ultrasonography can also be used to evaluate the patency of blood vessels and whether they are combined with structural problems such as vascular stenosis. Pay attention to the prevention of heart disease, hypertension, diabetes and stroke, and take timely measures to control any problems, either medication or non-medication, to achieve early detection, early diagnosis, early treatment and early prevention of diseases. 2. Healthy living and balanced diet. Avoid taking too much salt and animal fat, and take a balanced intake of protein, dietary fiber, vitamins, minerals, etc. Regular life, avoid smoking, alcohol and other bad habits. 3, moderate exercise, brain exercise. Adhere to exercise will make the body and brain energetic. Pay attention to the reasonable arrangement of exercise programs in conjunction with their physical state and preferences. Especially the elderly, pay attention to their physical fitness, and be sure to prevent trauma. Prevent falls. Repeated traumatic brain injuries are a major risk factor for dementia, in addition to direct damage to brain tissue. In addition, besides the body, our brain also needs exercise. Reading, painting, calligraphy, writing, playing games and other educational activities can keep the brain excited and activated. Intellectually stimulating activities can enhance the function of brain cells and make the connections between neurons stronger. Having and maintaining a hobby not only gives physical and intellectual exercise, but also tests one’s learning ability, and helps to detect early and mild lesions in a timely manner while protecting memory. Older people with early stage dementia often quit their original favorite job or hobby early on various excuses or for no reason, which is actually a sign of declining brain function. 4. Integrate into society and feel comfortable. The elderly often have to face retirement, the death of friends and relatives and other loss experience, many people thus got depression, or even a stumble. At this time, the psychological support of family and friends can relieve the pressure faced by the elderly in life, so that negative emotions can be cathartic. Appropriate participation in leisure activities and social activities by the elderly can make their bodies and minds gain more enjoyment and pleasure and release stress. And increasing the understanding of new things and constantly solving new problems faced in the activities is a way to maintain, exercise and improve the thinking, judgment, analysis, coordination, synthesis and reaction ability of the elderly. Therefore, active participation in social interactions, more communication with people and participation in group activities in the community have a very positive effect on dementia prevention. Likewise, we have found that reluctance to interact with people and withdrawal of social behaviors often suggest that there may be a significant decline in memory as well as intelligence, which is sometimes one of the early signs of dementia. It’s not too late for the sun to shine. Older people can still effectively prevent dementia and live a wonderful old age as long as they maintain an optimistic attitude and arrange their lives rationally.