Brain metastases are the most common malignant lesions in the skull and are caused by malignant tumor cells from other parts of the body that metastasize through the blood system to grow in the skull. According to statistics, brain metastases occur in about 20-40% of patients with malignant tumors. When brain metastases are found, a comprehensive evaluation of the intracranial lesions should be performed first. Secondly, every possible effort should be made to determine the primary site. The determination of the primary site is of key importance to the treatment of brain metastases. Since most chemotherapeutic drugs have difficulty crossing the blood-brain barrier to enter the skull to kill the tumor cells, surgical treatment is of great importance. Surgical treatment of brain metastases is used for: (1) single or multiple brain metastases with obvious local occupying effect and possible brain herniation; (2) single brain metastases or multiple metastases adjacent to each other, located in surgically accessible areas, in good general condition and with stable extracranial tumors. For these patients, surgery combined with postoperative whole-brain radiotherapy can improve the intracranial local control rate, and the effect is better than surgery alone or whole-brain radiotherapy alone; (3) Patients with intracranial lesions suspected to be metastases, and the pathological diagnosis cannot be obtained extracranially, stereotactic biopsy surgery or open biopsy surgery is feasible. Due to the progress of modern microsurgery, surgery has become an active measure for the treatment of brain metastases, and postoperative treatment with radiation therapy and chemotherapy can significantly prolong the survival time and quality of life of some patients.