Bone metastases from breast cancer are mostly seen as multiple osteolytic lesions. Bone metastases with pain seriously affect patients’ quality of life, but bone metastases themselves are usually not directly life-threatening; there are many effective treatments and patients without combined visceral metastases have a relatively long survival. How can bone metastases be detected? Bone radionuclide scan (ECT) is the most commonly used method for initial screening of bone metastases. It has the advantages of high sensitivity, early detection of abnormal bone metabolic foci, and whole-body imaging. However, it also has the disadvantages of low specificity, cannot indicate osteogenic or osteolytic lesions, and cannot show the extent of bone destruction. It is generally used for routine initial screening and diagnostic examination of breast cancer with suspected bone metastasis such as bone pain, pathological fracture, elevated alkaline phosphatase or hypercalcemia, and also for routine examination of patients with locally advanced breast cancer (T3N1M0 or above) and recurrent metastatic breast cancer. To further clarify whether there is metastasis or not, further bone X-ray, CT scan, magnetic resonance imaging (MRI) and other examinations are needed. X-ray is the basic method to diagnose bone metastasis, which has the advantages of visualization and high specificity, but also has the disadvantage of low sensitivity. X-rays and CT scans can be used to evaluate the efficacy of treatment for bone metastases. Magnetic resonance imaging (MRI) is less specific than CT, but MRI of the spine is important to understand whether the spinal cord is compressed and the stability of the spine, and to understand the indications for surgery and radiotherapy for bone metastases. However, the special imaging principle of MRI makes it possible to diagnose false positives, so MRI abnormalities alone cannot diagnose bone metastases. Bone biopsy is the gold standard for the diagnosis of bone metastases from breast cancer. For clinically suspicious bone metastases, especially those single bone lesions without soft tissue metastases or visceral metastases, puncture biopsy should be pursued for definite pathological diagnosis. In conclusion, for the clinical diagnosis of bone metastasis of breast cancer, ECT can be used as the initial screening examination, X-ray and CT can clarify whether there is bone destruction, and MRI can help to understand the impact of bone metastasis on the surrounding tissues, especially the stability of the spine.