At present, the incidence rate of breast cancer in China has accounted for the first place of women’s malignant tumors, and shows a trend of rejuvenation. Early diagnosis and treatment are crucial for breast cancer patients.The 5-year survival rate of stage I breast cancer diagnosis and treatment is about 96%; the 5-year survival rate of stage II is about 84%; however, when it comes to stage III, the 5-year survival rate drops sharply to 41%. How to effectively prevent, timely detect, early diagnose and treat breast cancer? Regular breast screening is essential. Currently, the more common screening tools are: breast ultrasound, mammogram and breast magnetic resonance imaging (MRI). Breast ultrasound Young women have denser breast tissue, and when this dense gland is examined by mammography, the gland tends to cover the tumor and reduce the diagnosis rate, so breast ultrasound is the preferred screening method for young women. Breast color ultrasound has its unique advantage in determining the nature of breast lumps, especially cysts, the diagnosis rate can be as high as 95%. Moreover, breast color ultrasound has no radiation, even during pregnancy and breastfeeding, it is the safest way to check, no need to worry about radiation. However, breast ultrasound is not accurate enough to determine small calcifications. Mammograms It is generally recommended that women begin mammograms in conjunction with breast ultrasound at age 40. As the glandular structure of women under 35 years old is relatively dense and rich in fibrous tissue, it often shows dense shadows of the breast and lacks specific level contrast during examination, therefore, the significance of mammography for women under 35 years old is not as great as that for women over 35 years old. However, after the age of 40, the glands gradually begin to fatty, and the advantages of mammography are gradually manifested. Mammography is especially important for the diagnosis of early carcinoma in situ, which is often not palpable and is mainly manifested by clustered calcifications, which is precisely the advantage of mammography. Therefore, breast ultrasound and mammography have their own strengths, and the combination of the two can improve the diagnosis rate of breast tumors by complementing each other. Breast MRI MRI is radiation-free, highly accurate and suitable for women of all ages. However, it is relatively expensive and is not routinely used for breast screening. However, breast MRI can determine tiny lesions in the breast before breast cancer is treated with breast-conserving surgery, making breast MRI a common test for breast cancer patients preparing for breast-conserving surgery.