Brain metastases (BM) are a common complication of some malignant tumours. Surgery is the most traditional form of neurosurgical treatment for cranial tumours and plays an irreplaceable role. However, the recurrence rate after conventional surgery for cranial metastases is often high. Increasing clinical and pathological evidence supports the idea that these tumours are not clearly demarcated from normal brain tissue, leading to the development of "supramarginal resection" of brain metastases. Initially limited to non-functional areas for the protection of brain function, it has now been introduced into functional areas with sophisticated tools such as electrophysiological detection, navigation systems and intraoperative arousal. Efforts have been made to optimise the relationship between maximum tumour resection and preservation of brain function, such as the surgical approach. By reviewing a large number of studies related to supramarginal resection in BM, the article systematically describes the occurrence and development of this surgical concept.