Hysteroscopic surgery can directly detect lesions in the uterine cavity, which is more intuitive, accurate and reliable than scraping, hysterosalping and ultrasound, reducing missed diagnoses and improving diagnostic accuracy, as well as taking biopsies and performing simple treatment. Principle of hysteroscopy: The uterine cavity is dilated through various dilating media, and the cold light source is introduced into the uterine cavity through the hysteroscope with optical lenses and optical fibers to examine and diagnose the physiological and pathological conditions in the uterine cavity under direct vision, which has become the standard surgical mode for treating lesions in the uterine cavity. Indications for hysteroscopic surgery: 1. Abnormal uterine bleeding: excessive and frequent menstruation, prolonged menstruation, irregular uterine bleeding, bleeding after menopause, bleeding before and after menopause, etc. 2. Infertility of unknown origin. 3.Multiple habitual abortions and multiple pregnancy failures. 4.Suspected uterine adhesions. 5.Suspected uterine malformation or intrauterine abnormality. 6.Suspected intrauterine foreign body residue. 7, review the intrauterine device situation. 8.Follow up after intrauterine surgery. 9.Checking of tubal patency, treatment of adhesions and sterilization by embolization. 10.Observation of changes in the endometrium. Contraindications to hysteroscopic surgery: 1.Acute or subacute pelvic infection. 2.Active. Uterine bleeding (massive). 3, Recent history of uterine perforation or uterine repair. 4, Reproductive tract tuberculosis without appropriate anti-tuberculosis treatment. 5.Body temperature ≥37.5℃. 6.Severe heart, lung, liver, kidney and other organ diseases. 7.Infiltrating official neck cancer. 8.Hematological disease.