The prevailing international standard for the time of embolization of cerebral thrombosis was performed within 8 hours of onset before 2018, and in 2018 the latest conclusions were reached in Europe and the United States that the time of embolization could be extended to within 24 hours of onset, and our country subsequently updated the strategy for the time of embolization, drawing on the treatment methods of Western countries. However, the extension of the time limit for thrombus retrieval must be improved before deciding to retrieve the thrombus by multimodal CT for brain tissue assessment, and only the presence of cerebral ischemic semidark zone tissue, that is, the presence of dying but still living brain tissue in the area of lesioned brain tissue, is suitable for thrombus retrieval treatment. If there is no ischemic semidark zone or the onset time is more than 24 hours, embolization should not be performed, otherwise severe cerebral hemorrhage will occur and the significance of embolization will be lost.