Severe eclampsia is caused by the patient’s uterine spiral small arterial structural abnormalities, resulting in placental ischemia, hypoxia, the release of a variety of placental factors, placental factors into the maternal circulation, promoting the activation of inflammatory response and vascular endothelial damage, causing the patient to develop the symptoms of tonic-clonic convulsions or coma, usually accompanied by hypertension, liver function impairment, renal function impairment, and visual impairment and other conditions. When convulsive seizures, should prevent lip and tongue bite or the occurrence of tongue fall, clean up oral secretions, keep the airway open, and static magnesium sulfate antispasmodic, lowering blood pressure, prevention and treatment of complications. The safety of mother and baby is ensured as much as possible, while the mother and fetus are closely monitored during treatment, and termination of pregnancy can be considered once the convulsions are controlled. Neurological damage secondary to cerebral hemorrhage and cerebral ischemia can occur in patients with severe eclampsia, may persist, and is a major cause of death. It is recommended that when a pregnant woman develops preeclampsia, she should seek prompt medical attention for examination and active treatment to avoid the occurrence of severe eclampsia.