Alzheimer’s disease is a progressive neurodegenerative disease and the most common type of dementia. After the onset of the disease, patients slowly develop cognitive dysfunctions such as memory, language, calculation, and behavior because of continuous brain nerve atrophy, and eventually evolve into full-blown dementia. Moreover, this disease is currently incurable and can only be alleviated to some extent through multiple pathways. The emergence of Alzheimer’s disease is related to genes, lifestyle, and environmental factors. Some diseases also increase its probability, such as hypertension, obesity, and diabetes, because they may cause cerebrovascular disease, which in turn damages nerve cells, especially diabetes, whose damage to the central nervous system is increasingly valued. When the body is in a long-term hyperglycemic state, metabolic disorders, vascular damage, and lack of neurotrophic factors can occur, which in turn can directly or indirectly interfere with the synthesis of nerve cell proteins and lead to atrophy of nerve cells. At the same time, diabetic patients are also prone to hypoglycemia, which can cause nerve cells to die because they cannot get enough energy, and in severe cases, it can also cause necrosis and softening of large areas of brain tissue, leading to brain atrophy and dementia. In addition to these, insulin resistance and insufficient insulin action are also among the reasons why diabetes damages the central nervous system, and the way to prevent these diseases is to get the blood sugar under stable control as early as possible. Bariatric surgery is one of the current standard treatments for diabetes that can keep blood sugar within the normal range in a long-term, stable manner, and it has been continuously developed and refined over the decades and has been affirmed in most parts of the world.