The cause of breast cancer is still unclear, and there is no good primary prevention method at present, but we should pay attention to the secondary prevention of breast cancer, that is to say, early detection of the disease, and the detection of cases by census, which can effectively improve the survival rate of breast cancer patients. There is a certain relationship between the occurrence of breast cancer and obesity, high-fat diet, over-nutrition, over-drinking, etc. Therefore, we should try to avoid these factors, pay attention to light diet, less alcohol, and exercise more to avoid over-nutrition. Breast ultrasound combined with molybdenum target is generally recommended as a screening method in China. Early breast cancer symptoms are often not obvious, but may appear breast lumps, nipple overflow, once you find breast discomfort symptoms, be sure to go to the hospital in time, can be diagnosed early treatment.