The most common causes of vaginal relaxation are large fetal head, poor uterine contraction and small vaginal opening, so the labor process may be longer. During the delivery of the fetus from the vagina, it will tear the ligament, fascia or vaginal wall muscles of the pelvic floor, leading to vaginal relaxation. After delivery, the fetus takes part in heavy physical labor too early, stays in bed, and the pelvic floor muscles can't recover well, which will lead to postpartum vaginal relaxation, urine overflow after skipping rope, coughing and sneezing, which will press the rectum backwards, affect defecation and appear persistent anal dilatation. For women who give birth naturally, it is suggested to do rehabilitation treatment of pelvic floor muscles to promote the contraction and recovery of pelvic floor muscles.