The etiology of severe preeclampsia has not been fully elucidated and is currently thought to be related to insufficient recasting of small uterine spiral arteries, inflammatory immune hyperactivation, and genetic factors. Severe preeclampsia belongs to hypertensive disorders of pregnancy, which is defined as high blood pressure (systolic blood pressure ≥160 mmHg, or diastolic blood pressure ≥110 mmHg), positive urinary proteins, accompanied by thrombocytopenia, hepatic and renal impairment, pulmonary edema, and other manifestations of organ damage. The etiology of preeclampsia has not been fully elucidated, and it is currently believed that the impaired infiltration ability of extravillous trophoblast cells in preeclampsia leads to impaired shallow placenta implantation and recasting of the uterine spiral artery, increased vascular resistance, and hypoxia due to decreased placental perfusion, causing the release of placenta factors. Placental factor enters the maternal circulation and promotes an excessive inflammatory immune system, as well as causing damage to the vascular endothelium and spasm of small arteries throughout the body, resulting in elevated blood pressure and organ damage. There is a certain familial predisposition to severe preeclampsia, which may also be associated with nutritional deficiencies such as lack of calcium, magnesium, zinc and selenium. It is recommended that patients with severe preeclampsia seek prompt medical attention and follow doctor’s instructions for examination and treatment.