It is recommended that the IUD be performed within 3-7 days after the end of menstruation because the uterine lining is relatively thin during the 3-7 days after the end of the night, and the stimulation of the endometrium during the IUD is relatively less, and the bleeding after the IUD is relatively less. It is recommended to wait for 42 days after delivery for the IUD to be inserted after the malignant dew is completely over and the uterus has fully recovered. If it is a cesarean section, it is recommended to consider IUD after six months after the operation. It takes about six months for the uterus to fully recover after a cesarean section, so it is recommended to wait until the uterus has fully recovered before having an IUD. Before IUI, women must undergo routine leucorrhea examination. If women suffer from gynecological inflammation, it is recommended to treat the gynecological inflammation first and consider IUI after the gynecological inflammation has fully recovered, so as to avoid the process of IUI from causing upstream infection and forming endometritis.