Regardless of craniotomy or intervention, there is a consensus regarding the timing of surgery for the treatment of ruptured intracranial aneurysms. Once diagnosed, it should be treated urgently to avoid observation and waiting for death by secondary hemorrhage. For non-ruptured aneurysms, surgery should be performed in a limited period of time if there are symptoms of compression or rupture, or asymptomatic treatment or dynamic observation. For ruptured intracranial aneurysms, treatment during the chronic or resorption phase of bleeding is definitely less risky than treatment during the acute phase of bleeding. There are three main reasons for this: (1) the rupture of the aneurysm during the acute phase of hemorrhage is blocked by an unstable thrombus, which can easily rupture again during the operation; (2) during the acute phase of hemorrhage, especially during the period from 4 days to half a month after hemorrhage, many patients have cerebral vasospasm, i.e., the cerebral artery is stimulated by subarachnoid hemorrhage to spasm and become thin, which can sometimes aggravate this spasm when intervention is performed, resulting in insufficient distal cerebral blood supply or even cerebral infarction; if craniotomy due to severe cerebral edema affects the surgical exposure operation and increases brain injury. (3) The hematological system of patients in the acute phase of hemorrhage is in a hypercoagulable state, and thromboembolic complications resulting in ischemic stroke can easily occur during interventional treatment. Given the high risk of treating intracranial aneurysms during the acute phase of hemorrhage, should we wait 3 weeks for the hemorrhage to absorb before treating it? The answer is no. According to statistics, the rebleeding rate within 2 weeks after ruptured intracranial aneurysm is as high as 20%, and many patients often die of secondary bleeding before the first bleed is absorbed, thus losing the opportunity for surgery. In addition, combined vasospasm is not an absolute contraindication to intervention in the acute phase of intracranial aneurysm. Such spasm often makes it more difficult to access the aneurysm with a microcatheter. While it is certainly easier to perform intervention after the spasm has subsided and the artery has returned to its normal diameter, some patients cannot wait for the spasm to slow down and bleed again, unless it is a very severe and extensive vasospasm. Of course, after embolization of the aneurysm, some patients will still be disabled and die due to intractable vasospasm. Craniotomy may reduce vasospasm by releasing intraoperative hemorrhagic brain fluid. Therefore, the ruptured intracranial aneurysm should be operated within 3 days in the acute stage regardless of craniotomy or intervention, or within 1 week if it is graded as grade 3 or less.