After delivery, the vagina will discharge meconium tissue and cervical mucus, and within three days after delivery, the discharge contains more blood and is bright red in color. From the 4th to the 10th day, the color of the discharge will slowly become lighter, because at this time, the discharge contains less blood, and it is all plasma discharge. After 10 days postpartum, there is almost no blood, but basically a large number of white blood cells, bacteria, necrotic meconium and epithelial tissue, which is basically eliminated by the 4th to 8th week postpartum. If the discharge is still not clean even after 8 weeks, and accompanied by a strong odor, it may be caused by placenta residue in the uterus after delivery, or caused by factor endometritis. At this time, the patient needs to go to the hospital in time, through the ultrasound examination of the uterus whether there are abnormalities, after a clear diagnosis, according to the cause of the treatment.