Cranial clamping is certainly major surgery, and it is a category 4 surgery, the highest level of surgery, according to the neurosurgical grading of surgery. Cranial clamping is actually an acronym. In terms of specialized neurosurgical medicine, its full name is cranial aneurysm clamping. This is a more thorough method of treating intracranial aneurysms and is able to completely cure intracranial aneurysms. Intracranial aneurysm is generally a congenital disease of the intracranial blood vessels, or it can be caused by long-term hypertension, which results in the endothelial lining of the intracranial arteries expanding beyond the outer membrane of the arteries. This pathologic vascular structure is prone to rupture when blood pressure increases, resulting in spontaneous subarachnoid hemorrhage, which is a serious threat to the patient’s life. Therefore, once a ruptured subarachnoid hemorrhage is detected, it is necessary to be on high alert for the presence of intracranial aneurysm, and further angiography should be performed. If intracranial aneurysm is found, craniotomy aneurysm clamping surgery should be actively carried out.