IUD, the professional term for intrauterine device, abbreviated as IUD, is a device placed in the female uterine cavity for contraception, mainly divided into inert IUD, including stainless steel ring, plastic mixed ring, uterine-shaped birth control device, etc., and active IUD, including copper-containing IUD and drug-containing IUD.IUD mainly plays a contraceptive role, but progesterone-containing IUD can also be used to inhibit endometrial hyperplasia, reduce the amount of menstruation, etc. IUDs are mainly used as contraceptives, but progesterone-containing IUDs can also be used to inhibit endometrial growth and reduce menstrual flow. The mechanism of action of IUD is to interfere with the physiological state of the endometrium, preventing the follicle from implanting and developing. Drug-free IUD causes local inflammatory reaction in the uterine cavity, and copper-containing IUD can locally release copper ions, which have the effect of killing sperm and inhibiting sperm activity. Progesterone-containing IUDs cause premature metaphase-like changes in the endometrium and glandular atrophy, affecting the fertilization of the egg, making the cervical mucus sticky, affecting sperm transport and capacitation. There are many materials and forms of IUDs, and progesterone-containing IUDs can also be used to inhibit endometrial hyperplasia and reduce menstrual flow. Lower abdominal pain, vaginal bleeding, and downward displacement and shedding may occur after the IUD is placed. It is necessary to choose the appropriate IUD according to the patient’s condition, uterine morphology, and specific requirements. Pregnancy should be excluded before placing the IUD, and the duration of IUD placement varies, and it should be removed within 1 year after menopause. If the patient needs to have an IUD placed or removed, he/she should go to the hospital, complete the relevant examinations and follow the doctor’s instructions for treatment.