Hysteroscopy as an important component of minimally invasive gynecological surgery is becoming increasingly popular in clinical practice. As a minimally invasive surgical method under direct vision, it has quick recovery, does not affect the endocrine function of ovaries, and has become an indispensable part of modern gynecological clinical diagnosis and treatment with its advantages of intuitive accuracy, rectification of the anatomical morphology of the uterine cavity, and replacement of hysterectomy to cure abnormal uterine bleeding, etc. It is regarded as It is known as the ideal surgical procedure for the treatment of benign intrauterine lesions. 1.Transcervical resection of endometrium (TCRE): The main indications are dysfunctional uterine bleeding (DUB), which is not treated by medication. TCRE for DUB is based on the destruction of the entire endometrium and part of the muscle layer beneath it, preventing endometrial regeneration and achieving a clinical effect of amenorrhea or reduced menstruation. Three steps are generally required, namely: (1) hysteroscopy and endometrial biopsy to exclude atypical endometrial hyperplasia and endometrial cancer; (2) endometrial pretreatment to inhibit endometrial hyperplasia, including pharmacological pretreatment and mechanical pretreatment. Drug pretreatment can shrink the endometrium, reduce the size of the uterus, reduce the regeneration of blood vessels, shorten the operation time and reduce bleeding, currently the commonly used drugs are endometrium (2.5mg orally, 2 times/week, 4-12 weeks) and GnRH-a (such as Noraid 3.6mg subcutaneously, once every 28 days, 1-3 times) The latter has the best effect; mechanical pretreatment before surgery negative pressure suction can thin the thickness of the endometrium; ③ excision of the endometrium, must be carried out according to certain procedures, first vertical electrodes cutting the bottom of the uterus or roller ball electrodes electrocoagulation of the endometrium at the bottom of the uterus, cutting the uterine horn each time shallower chipping and scraping, until cutting the endometrium to avoid perforation. Once the fundus has been treated, the endometrium of the uterine wall is removed with a 90° cutting ring or a band electrode, preferably treating the posterior wall first and systematically cutting the endometrium in a counterclockwise direction starting at 9 o’clock, first cutting the upper third, followed by the middle third and finally the lower third up to the cervical canal. The depth of excision depends on the thickness of the endometrium and is aimed at cutting 2-3 mm below the endometrium, which is sufficient to remove the entire endometrium without cutting into the larger vessels. However, DUB patients with fertility requirements should not undergo TCRE treatment. The results of Beijing Fuxing Hospital showed that the total effective rate of menstrual improvement was 94.5%, including 25.8% amenorrhea, 68.7% reduction in menstrual volume, and 97.6% of combined anemia was corrected. 92.3% of the patients were satisfied with the surgical results. 2.Hysteroscopic endometrial polypectomy (transcervicalresectionofpolyp,TCRP): endometrial polyp is a common cause of abnormal uterine bleeding and infertility, the usual treatment is blind curettage, but often encounter the problem of failure to remove. The basal layer can prevent its persistence and recurrence. The lining and the polyp are aspirated with a negative pressure suction device before surgery, and the lining covered on the surface of the polyp is aspirated away, leaving only the interstitial tissue of the polyp, which is significantly reduced in size and can be easily removed from the tip or the base with an electrosurgical ring. 3.Hysteroscopic submucosal myomectomy (transcervicalresectionofmyoma,TCRM): At present, submucosal myoma is divided into three types according to the relationship between myoma and myometrium, type 0 is submucosal myoma with tissues, which does not extend to myometrium; type I has no tissues, which extends to myometrium <50%; type II has no tissues, which extends to myometrium >50%. The microscopic difference between type I and type II is that the mucosa of the former migrates from the uterus to the myoma at an acute angle, and the latter at an obtuse angle. Submucosal fibroids are suitable indications for hysteroscopic surgery. tCRM does not disrupt the normal anatomy of the uterus, cures abnormal uterine bleeding, and improves the reproductive prognosis of the patient. The following conditions are considered for the selection of indications: (1) excessive menstrual flow or abnormal bleeding; (2) uterus limited to 10 weeks gestation size and uterine cavity limited to 12 cm; (3) submucosal fibroids generally limited to 5 cm in size; (4) submucosal fibroids generally limited to 5 cm in tip size; (5) submucosal fibroids prolapsing from the vagina of any size or tip thickness. For type 0 submucosal leiomyoma, we can cut off the root of the tip and remove it or reduce the size of the leiomyoma and then cut off the root of the tip and remove it. The procedure is often staged for type I and II submucosal fibroids, with a window cut through the muscle tissue on the surface of the fibroid to form a window. structure, cure abnormal uterine bleeding, and improve the reproductive prognosis of the patient. 4, hysteroscopic hysterectomy (transcervicalresectionofsepta,TCRS): the previous treatment of symptomatic septum surgery for Jones or Tompkins transabdominal hysteroplasty, traumatic, slow recovery, long postoperative contraceptive time, it takes 3-6 months to repair the uterine trauma, and laparotomy can occur adhesions, increasing the infertility factor. TCRS is a new method to treat infertility by restoring the anatomy of the uterine cavity in a minimally invasive environment, and the septum is a non-vascular embryonic residual tissue with no obvious bleeding. During surgery, the cutting electric knife moves forward, that is, retrograde cutting, unlike the prograde cutting in the direction of the operator in TCRE, TCRP or TCRM, attention should be paid to the depth of penetration and the direction of the electrode, left and right reciprocal cutting, pay attention to the symmetry of the uterine cavity, cut to the base of the mediastinum, pay attention to not cutting too deep to avoid perforation of the uterus, intraoperative ultrasound or laparoscopic monitoring, postoperative placement of the IUD, two months The IUD will be removed after two months. 5, hysteroscopic hysterectomy (transcervical resection of adhesion, TCRA): hysterectomy may cause dysmenorrhea, interfere with normal fertility and menstrual pattern, in the past, usually using scraping, dilating rods to separate hysterectomy adhesions and other blind methods can not obtain satisfactory clinical results, and TCRA is a direct vision of the uterine cavity rectification surgery, can TCRA is a corrective surgery of the uterine cavity under direct vision, which is capable of separating or removing cavity adhesions, restoring the normal anatomical shape of the uterine cavity, correcting menstrual abnormalities and restoring fertility to infertile patients, and has become the standard treatment for cavity adhesions. The operation is difficult and prone to uterine perforation, so it is best to combine laparoscopic B-ultrasound monitoring during the operation. 6.Hysteroscopic removal of uterine foreign body (transcervicalresectionofuterineforeignbody,TCRF): hysteroscopic diagnosis and treatment of intrauterine foreign body, precise location, no damage to the normal endometrium, applicable to the embryo and embryonic tissue residual mechanization, fetal bone residue and lost or fractured intrauterine birth control uterine foreign body removal or Removal. With the continuous development of hysteroscopic technology, this intuitive and accurate minimally invasive surgical method will be more practical, safer and shorter, which will benefit more women.