Indications: 1, abnormal uterine bleeding: heavy menstruation, irregular bleeding, prolonged menstruation, postmenopausal bleeding, etc.; 2, abnormal intrauterine sonographic findings: ultrasound suggests abnormal occupancy of the uterine cavity (endometrial polyps, submucosal leiomyomas, placental remnants, uterine foreign bodies, etc.); 3, infertility: uterine cavity status; 4, recurrent spontaneous abortion: uterine deformities, longitudinal septum, uterine stenosis, laxity of the internal os of the uterine cervix, and other conditions and Evaluation; 5. Amenorrhea, menorrhagia, severe dysmenorrhea: especially previous intrauterine surgery or suspicion of cervical stenosis, uterine adhesions, etc. Examination and operation time: usually within 5 days after menstruation.