Edema after brain tumor surgery has a certain mortality rate, but it also depends on the site of edema and the patient’s physical condition, timely prevention or de-oedema can effectively reduce the mortality rate. Edema after brain tumor surgery is a common postoperative complication. Since edema increases intracranial pressure and compresses important tissues such as brainstem, the mortality rate is high. Edema may also increase the risk of postoperative mortality in middle-aged and elderly patients or in patients undergoing brain tumor surgery who have underlying medical conditions. If edema occurs after brain tumor surgery, effective diuresis and dehydration can be achieved through the use of drugs such as mannitol or furosemide, and decompression surgery with debridement flap can relieve the symptoms of intracranial edema if necessary, thus relieving the compressive injury and high intracranial pressure. Edema needs to be prevented in the postoperative period after brain tumor surgery, and at the same time, you can choose the appropriate way for effective prevention and treatment under the guidance of the doctor.