Breast cancer is one of the most common malignant tumors in women. Currently, about 1.2 million women worldwide suffer from breast cancer and 500,000 women die from it every year. Breast cancer seriously affects women’s health and life, and how to effectively control its occurrence and development has become an urgent task. In its prevention and treatment, early detection, diagnosis and treatment are the keys to improve the prognosis and survival rate of breast cancer patients. The national free breast cancer screening for rural women has been launched, which will help detect breast cancer patients at an early stage, curb the growth of breast cancer and improve the effectiveness of breast cancer treatment. Breast cancer screening is mainly clinical physical examination and mammography and ultrasound examination. The target population is mainly women over 35 years old, and those with family history of breast cancer and other high-risk factors are the key targets of screening. Mammography is the most important tool in breast cancer screening. It uses the physical properties of X-rays and the different densities of human breast tissues from different angles to take pictures of the breast, projecting the image of the breast on the X-film and reflecting the structure of the whole breast comprehensively and clearly. Its correct rate of diagnosing benign and malignant breast tumors is more than 85% to 90%. It has obvious advantages in early diagnosis of breast cancer, and is the preferred imaging diagnostic method in addition to clinical physical examination. The World Health Organization recommends that women over 50 years of age should have mammography once a year, women between 40 and 49 years of age once every 1 to 2 years, and women between 35 and 40 years of age should have mammography once as basic information and as a control in the future, and the peak age of breast cancer incidence in Chinese women is advanced. In young women, breast tissue is dense and mammography is not easy to detect lesions, so color ultrasonography can be used as a means of early diagnosis of breast cancer; breast ultrasonography is an economic, easy, non-invasive and painless examination method, which is more suitable for young women, especially pregnant and lactating women, but less sensitive than mammography in detecting microcalcifications. The two complementary examination methods can improve the early detection rate of breast cancer. Currently, the combination of mammography and ultrasound is considered the gold standard for breast cancer screening. Regular breast self-examinations can improve the detection rate of early breast cancer. Breast self-examination should be done once a month, and the best time should be within 7 to 10 days after menstruation, when the breast is looser and less distended and painful, and abnormalities can be easily detected. Women who have stopped menstruating can choose a fixed time of the month for examination. Each self-examination should be compared with previous self-examinations, and abnormalities such as breast or underarm lumps, bloody nipple overflow, etc. should be promptly sought so as to achieve early detection and early diagnosis. It is worth mentioning that breast self-examination is not a substitute for regular breast screening because many early breast cancers can have no clinical manifestations. Mammography and breast ultrasound can only detect the lesion and make a preliminary judgment on its benignity or malignancy from the perspective of imaging. Histological diagnosis is done by obtaining biopsies from breast lesions through minimally invasive biopsy, puncture biopsy or open biopsy, and then asking the pathologist to perform pathomorphological examination under the microscope. The purpose is to determine the nature of the lesion, predict the patient’s prognosis and guide treatment. The more timely the treatment, the better the outcome. Some early stage breast cancer patients can be cured through treatment. For those early stage breast cancer patients with negative lymph nodes, small lumps and no high risk factors for recurrence, postoperative treatment can even be considered without radiotherapy, which not only saves patients from the pain of treatment but also greatly reduces the cost of treatment. Early detection and early diagnosis can minimize the damage brought by breast cancer to women, both from the perspective of treatment and economics. Let’s cherish breast health, pay attention to early detection of breast cancer and never miss the best time for treatment.