Hysteroscopy is a new, minimally invasive gynecological treatment technique for the examination and treatment of the uterine cavity, a fiberoptic light source endoscopy, which is now widely used in the diagnosis and treatment of gynecological diseases. The factors of female infertility are complex, including age factor, mental factor, nutritional factor, immune factor, abnormal development of reproductive system, etc. Hysteroscopy is an important tool for diagnosing uterine etiology of infertility, and also has important therapeutic value. It has good diagnostic and therapeutic effects for infertility of uterine etiology caused by various reasons. 1. Uterine fibroids Endoconvex fibroids can lead to uterine deformation, submucosal fibroids as foreign bodies interfere with the implantation of pregnant eggs, hysteroscopy determines the location of fibroids and plays a guiding role in determining the need for surgery and choosing the surgical method, while ultrasound examination can only diagnose the size and approximate positioning of fibroids before surgery, and HSG can only suggest filling defects in the uterine cavity or uterine cavity deformation. In addition to TB, most of them are secondary infertility patients with previous history of uterine scraping. Hysteroscopy is the gold standard for the diagnosis of uterine adhesions, which can be directly diagnosed for less than II degree of uterine adhesions, but for more than III degree of adhesions, hysteroscopy can only show the cavity below the adhesions, which can accurately determine the site and degree of adhesions in cooperation with ultrasound. For mild uterine adhesions, high pressure injection of uterine expansion fluid can break the membrane-like adhesions, and for moderate to severe adhesions, treatment can be achieved by scissors or electric cutting of the adhesions. 3, endometrial polyps Endometrial polyps often lead to inappropriate menstrual cycle, and bleeding before and after menstruation, because endometrial polyps have clear morphological changes, experienced physicians through the hysteroscopy can be basically clear endometrial polyps, even the 0, 1cm polyps at the opening of the fallopian tube, can be seen at a glance, ultrasound on larger polyps, can suggest strong echogenicity of the endometrium, but not a clear diagnosis, the diameter of 0, 1 ~ 3, 0cm The polyp can be removed under direct vision while examining, and the rate of endometrial polyp detected by this department and pathological diagnosis is as high as 82%, and some scholars even believe that hysteroscopy is the gold standard for polyp diagnosis. 4.Uterine malformation Pre-operative color ultrasound is affected by uterine cavity deformation or disturbance of uterine cavity line, and it is easy to confuse endometrial polyp, uterine cavity adhesion and uterine septum, hysteroscopy combined with color ultrasound can basically confirm the diagnosis of uterine malformation type, and hysteroscopy is especially suitable for checking complete and incomplete uterine septum. Hysteroscopic electrodesection can restore the shape of the uterine cavity and help to improve the poor outcome of pregnancy and miscarriage, allowing such patients to avoid the pain of open abdomen for uterine malformation correction. Hysteroscopic intubation can separate the adhesions at the opening of the fallopian tube and play a certain role in separating the adhesions, compared with the traditional method of tubal lavage. In contrast to hysteroscopic tubal lavage, the tube is inserted into the opening of the fallopian tube and several times or even tens of times the pressure is injected directly into the lumen of the fallopian tube, thus separating some adhesions and mild to moderate obstruction in the official cavity. Ultrasound and HSG are unable to suggest similar subtle intrauterine lesions. 6, endometrial hyperplasia The hysteroscopy shows limited or diffuse hyperplasia of the endometrium, sometimes in the form of multiple polyps, and the surface is rich in blood vessels. The abnormal distribution of endometrial vessels and limited endometrial hyperplasia reflect inflammatory changes of the endometrium and hormonal imbalance stimulation of the endometrium, which are closely related to pregnancy outcome and have some therapeutic significance when diagnostic scraping is given. In conclusion, hysteroscopy is the only method that allows in vivo observation of the endometrium compared to ultrasound, HSG, and diagnostic scraping, and provides a comprehensive view of the endometrium before sampling and treatment, allows follow-up of endometrial hyperplasia, and accurately assesses the endometrial response to medication. Under the appropriate dilation pressure, complications are rare. Hysteroscopy is an indispensable method to exclude cervical canal and intrauterine factors in infertility patients, and it is also safe, effective, simple and minimally invasive as a treatment.