Tumor is a local manifestation of systemic disease. Many modern examinations and tests have special uses in the diagnosis of malignant tumors. Often a simple routine examination may bring a lot of information. Some examinations have limitations in themselves and cannot be detected and diagnosed for some lesions. Therefore, performing more tests is a process that patients must go through to stage their tumors and is providing the basis for the next step in developing a treatment plan. One important feature that makes a malignant tumor malignant is metastasis and recurrence. Each tumor has its relatively common metastatic pathways and metastatic sites, and some tumors can have extensive distant metastases even when the primary tumor is small. It is very important to identify the site and size of metastasis to determine the stage of tumor. Tumor staging has decisive guiding significance for tumor treatment, and there are great differences in treatment principles for tumors with different staging. And tumor staging mainly relies on the size of the mass and the presence of distant metastasis to determine. Therefore, in clinical practice, it is often necessary to grasp the occurrence and development of tumor through comprehensive analysis of relevant examinations and tests.