Postpartum back pain has nothing to do with painless delivery, and most postpartum back pain is recovered in the hospital. Postpartum lumbago is related to the following reasons: 1, pregnancy leads to endocrine changes, the ligaments connecting the pelvis become relaxed, as the uterus increases, the abdominal support gradually increases, the center of gravity shifts forward, the sacrospinous ligaments become more relaxed, inducing lumbago; 2, after delivery, endocrine cannot return to the pre-pregnancy state in a short time, the pelvic ligaments are in a relaxed state, the abdominal muscles are sore and weak, the uterus is not completely regained, and after delivery 3, the second stage of labor due to the special position, with all efforts for several hours, causing huge pressure on the waist, poor excretion of dew after delivery, resulting in blood stagnation in the uterus, bending over to change diapers and breastfeeding will cause lumbago; 4, most of the time after childbirth maternal lying down, the uterus due to gravity backward, compression of the large lumbar muscle, coupled with a large number of lactation period tonic, waist fat increase, will also cause lumbago; 5, some 5, there are maternal overwork after delivery, standing for too long or sitting for a long time, etc., will also lead to lumbar muscle strain, lumbago; 6, uterine prolapse, calcium deficiency, lumbar disc protrusion, incorrect posture during breastfeeding or not completely relaxed, lumbar muscles in a state of tension for a long time, will also appear lumbago. Prevention should pay attention to breastfeeding and resting position, reasonable diet, calcium supplementation and postpartum rehabilitation exercises.