Tumor bone metastasis is a very common complication of malignant tumors. Autopsy shows that 85% of cancer patients have bone metastasis, among which the bone metastasis rate is higher in prostate cancer, breast cancer and lung cancer patients. After the metastasis of malignant tumor, it often leads to a series of clinical symptoms such as intractable pain, dysfunction, pathological fracture, high blood calcium, etc. Current methods of treating bone pain caused by bone metastasis such as analgesics, chemotherapy, hormone therapy, etc. have great side effects, and the effect is not ideal for patients in advanced stage. Although the application of external irradiation therapy can effectively treat bone pain, it is more effective in treating single bone metastases and is not applicable to extensive bone metastases. Internal radionuclide irradiation therapy is a kind of targeted treatment, which is simple, can be directly injected intravenously, with little damage to the surrounding tissues and few side effects, not only has good pain relief effect, but also has the effect of eliminating and shrinking bone metastases. The commonly used internal irradiation therapeutic nuclides are 89Sr and 153Sm. The efficiency of 89Sr and 153Sm in treating bone metastases is 80% to 90%, especially for patients whose primary tumors are prostate cancer, breast cancer and lung cancer, the efficacy is better. Moreover, 89Sr has less bone marrow suppressive effect than 153Sm. Therefore, 153Sm is recommended for patients with severe disease who want to relieve pain more quickly and whose families have relative financial difficulties, while 89Sr is recommended for patients with milder pain who want to maintain pain relief for a longer period of time.