Bone metastasis is the manifestation of malignant tumors transferring to the skeletal system through the blood pathway. Some patients with bone metastasis are diagnosed because of the symptoms of bone pain after examination, while some patients with bone metastasis have no symptoms, so how can tumor patients detect bone metastasis at an early stage? SPECT whole-body bone imaging in nuclear medicine is the preferred method for early detection of bone metastasis in tumor patients. Tumors prone to bone metastasis include breast cancer, lung cancer, prostate cancer and nasopharyngeal cancer, etc. Therefore, early diagnosis of bone metastasis is very important for the formulation of treatment plan for patients suffering from these tumors as well as the treatment effect of bone metastasis. Whole-body bone imaging has the following significant advantages: it can detect bone metastases 3-6 months earlier than X-ray; one examination can see the bones of the whole body, wherever there are lesions; the examination is safe, simple, non-invasive and painless. Patients with prostate cancer, breast cancer, lung cancer, etc., who are diagnosed by whole-body bone imaging and have no symptoms or bone metastasis should have bone imaging regularly (often for 1 year) so that they can have timely treatment for metastases. In addition, no matter what the situation is, if the tumor patients feel that they have bone pain somewhere, they should do whole body bone imaging immediately to see whether there is bone metastasis or not, so as to avoid misdiagnosis and mistreatment, which may cause troubles later on.