The clinical manifestations of ovarian hyperstimulation syndrome mainly include enlarged ovaries, ascites, hydrothorax, tissue edema, oliguria, etc. It may also be accompanied by poor appetite, nausea, vomiting and other symptoms. Ovarian hyperstimulation syndrome is a medical disorder, mainly due to the use of vasoactive ovulatory drugs during assisted reproduction, which dilates blood vessels throughout the body and causes extravasation of tissue fluid, resulting in pleural fluid, ascites, tissue edema, and oliguria, and in severe cases, the ovaries can be as large as 10 cm. Therefore, ovarian hyperstimulation syndrome is caused by drugs and therefore cannot be treated for its cause. The treatment should be discontinued as much as possible and the doctor should then treat the patient symptomatically to gradually relieve the stimulating effect of the drugs. In addition, ovarian size and abdominal volume should be closely monitored during ovulation promotion to avoid ovarian hyperstimulation syndrome.