Dementia is one of the common diseases among the elderly, which seriously endangers their health and has become the fourth cause of death after heart disease, tumor and stroke, bringing a heavy burden to the society and families. The early stage of dementia is mainly manifested as memory impairment. In China, the changes of memory impairment do not attract enough attention, and if the disease is allowed to develop further, it can become dementia, and there are few people who seek medical treatment in the early stage of dementia in old age, and once it is found, it is in the middle and late stage, which seriously misses the time of treatment. According to research, the rate of elderly people with dementia visiting professional institutions in Shanghai is less than 30%, and the rate of elderly people with mild dementia is as low as 5%-8%. The following conditions need attention in daily life: 1. Memory impairment: difficulty in remembering near events, mainly in recalling words or objects. 2, attention impairment: the ability to focus on a particular thing is reduced. 3.Decreased reasoning and abstract thinking ability: decreased ability to understand and respond to new things. 4.Decreased ability to use language: there is a barrier to understanding and expressing language, and sometimes there may be an inability to select appropriate words to express their intentions. 5.Visual-spatial dysfunction: decreased ability to draw geometric figures, or build blocks to test.