The complexity of brain tumors in terms of size, location and blood supply makes the surgery of brain tumor removal quite complicated. Most brain tumors can be removed in one surgery, but there are a few complex brain tumors that require multiple surgeries to achieve a more satisfactory removal. The tumors in the brain are located in the cranial cavity, which makes it necessary to cross the cranial barrier to reach the tumor first, and the scope of surgical exposure is somewhat limited. In some cases, multiple tumors are present in different parts of the brain, and only one tumor or its adjacent parts can be removed in one craniotomy. In some cases, although there is only one tumor, the tumor is relatively large and involves multiple sites, which is difficult to be removed through a single bone flap or access, and requires a separate access and bone flap to be removed in a single surgery. Although it is possible to use multiple flaps and accesses to remove multiple tumors or large tumors in the brain in one operation, the surgical trauma and risk are relatively high, and a staged operation can reduce the trauma and risk. Some tumors are rich in blood supply, so direct craniotomy may lead to hemorrhage or uncontrollable bleeding, so interventional methods are needed to block part of the blood supply to reduce the blood supply to the tumor. In general, brain tumor surgery is aimed to remove the tumor completely in one craniotomy, but for more complex brain tumors, sometimes multiple surgeries are needed to remove the tumor in a planned manner. Craniotomy for complex brain tumors requires individualized surgical plan according to the number of tumor sites, etc. In a few special cases, staged removal of brain tumors is one of the options to reduce surgical risks and trauma.