If the tumor brain metastasis has caused elevated cranial pressure, at this time the infusion of mannitol can play the role of dehydration, which has a certain therapeutic effect on improving the symptoms of coma. However, patients should also actively treat the original disease. When brain metastasis occurs, due to the compression of the tumor may lead to cerebral edema, intracranial pressure increases, at this time you can use mannitol and other dehydrating diuretics to reduce cerebral edema, reduce intracranial pressure, prevent the formation of cerebral hernia, alleviate the disease condition. In addition, you should actively treat the primary disease, such as surgery, chemotherapy and other ways. At the same time, we should also pay attention to strengthening nursing care, avoiding the occurrence of comorbidities, turning over and patting the back diligently, avoiding intrapulmonary infections and the formation of decubitus ulcers, and supplementing protein, vitamins and trace elements. When brain metastasis coma occurs, a reasonable treatment plan should be taken under the guidance of the doctor.