Breast cancer prevention can be started from the following four aspects: focus on healthy lifestyle: A. Reasonable diet structure. It is recommended to control the intake of animal fat and animal protein, and to consume vegetable fat as appropriate; to eat more fruits, vegetables, beans, mushrooms and fish; to drink less alcohol; to limit the intake of smoked food; to eat less salt, less than 6g of salt per day for adults; to eat more raw food and less canned food. B. Weight control and appropriate activities Overweight, obesity and weight change in adulthood have a significant impact on the occurrence of breast cancer, especially postmenopausal breast cancer. Overweight and obesity can be controlled through lifestyle changes. Therefore, by controlling body mass and physical activity, it can effectively reduce abdominal fat and control obesity, and control excessive weight gain in adulthood, thus effectively preventing the occurrence of breast cancer. C. Promote breastfeeding Avoid marriage and childbirth at an advanced age and promote breastfeeding, which can effectively reduce the incidence of breast cancer. D. Early diagnosis Emphasize routine breast self-examination and x-ray screening.