The invention discloses a uterine expander for treating obstetrics and gynecology uterine diseases, which belongs to the technical field of uterine expanders for obstetrics and gynecology. A uterine expander for treating obstetrics and gynecology uterine diseases includes; Shell; it is specifically columnar, and the upper diameter is smaller than the lower diameter, and semi-elliptical shallow openings are provided on the front and rear sides of the upper part to fix the duckbill. By pressing the airbag, the anti-off support, the expansion part and the limit locking mechanism can be attached to the cervical wall of the uterus under the action of air pressure, and the inner diameter of the expansion part can be adjusted according to the treatment cycle, so that the diameter of the expansion part can be adjusted at any time , to meet the treatment requirements, at the same time, under the state of internal air pressure, the ejector rod makes the connecting rod stretch out, so that the expanded part is stretched out and contacts the inner wall of the cervix, which can prevent it from falling off; the internal filling of the limit locking mechanism After the gas is released, the limit locking mechanism is opened to contact the bottom of the cervix, so that the inside and outside are combined, so that the device can be firmly attached to the cervix.