Abstract：Emergent cerclage may be defined as that performed in the setting of advanced cervical dilation with bulging membranes. It's an emergency operation that can save normal but immature fetus. Previous studies have indicated that the success rate of operation was 72.72%. That means emergent cerclage is a good remedy when the treatment of cervical incompetence is not timely. However, it may have serious complications if we can't grasp the opportunity and master the indications of the operation. So grasp the operation indications strictly, pay more attention in operative procedure and give good postoperative monitoring can improve the success rate of emergent cerclage.