Once acute foramen magnum hernia occurs: the first step is to use dehydrating drugs to relieve the condition, prevent further development of the condition and create time for surgery. A strong dehydrating agent should be rapidly pushed intravenously or dripped, and mannitol is commonly used in clinical practice. In patients with brain herniation, respiratory function will be affected, and immediate tracheal intubation and ventilator-assisted ventilation are required, with hyperventilation recommended to help reduce intracranial pressure. Aggressive preoperative preparations are then performed, such as preoperative skin preparation, preoperative indwelling catheterization, and signing the consent form for the treatment plan.