To summarize the perioperative nursing experience of a patient with a sudden aortic sinus aneurysm bursting into the right atrium at 11 weeks of twin gestation.Nursing key points included preoperative cardiac function monitoring of pregnant women,including aneurysm and rupture status monitoring,early waming of right heart failure and sudden death;intraoperative complication monitoring and prevention,postoperative accurate volume management and renal function monitoring,perioperative fetal monitoring,health education and discharge guidance.After 9 days of careful treatment and nursing,the patient recovered and was discharged from the hospital.After 36 weeks of follow-up,the twins were delivered by cesarean section.The mother and the baby were in good condition.