Breast cancer lymphatic metastasis can be determined by ultrasound, and for certain lymph nodes where ultrasound is inconvenient, it can also be determined by CT or MRI. During the ultrasound examination, it can be determined by looking at the breast lump, the condition of the lymph nodes around the breast, and the condition of the lymph nodes in the armpit. This is determined by looking for the presence of enlarged lymph nodes or the disappearance of lymph node gates, as well as the presence of abnormal blood flow signals and the fusion of lymph nodes into clusters. If no enlarged lymph nodes are found during ultrasonography or if it is impossible to clearly determine whether the tumor has metastasis, the sentinel lymph node examination method can be used to detect the tumor and inject contrast agent into the breast tumor during surgery to observe whether staining occurs in the surrounding lymph nodes, so as to determine whether the tumor has metastasis. Breast cancer patients should actively cooperate with the treatment, try to improve the discomfort symptoms of patients, and timely observe the state of patients to take targeted measures to improve the quality of life of patients.