With the rapid development of assisted reproduction technology, the success rate of IVF has been increasing in recent years. The average age of assisted conception patients is about 33 years old, and the clinical pregnancy rate of their single cycle has been stable at more than 55%, and the success rate of young people is even higher, and the clinical pregnancy rate of two thawed cycles after one fresh cycle can reach more than 80%, however, there are still about 10% of the patients who are not able to obtain pregnancy even after multiple embryo transfers, which is also the bottleneck problem hindering the further increase of pregnancy rate. However, there are still about 10% of patients who cannot obtain pregnancy after multiple embryo transfers, which is also a bottleneck that hinders the further improvement of pregnancy rate. Based on the current research progress and treatment characteristics both at home and abroad, we have explored the following effective experiences in improving the endometrial tolerance of patients with repeated implantation failures, except for the factors affecting the embryos. 1, Hysteroscopy and hysteroscopic treatment According to statistics, 25%-50% of patients with repeated implantation failure have abnormalities in the uterine cavity, and hysteroscopy, as a safe, minimally invasive and easy-to-master operation, can more intuitively describe the morphology of the uterine cavity, more accurately evaluate the state of the uterine cavity, and can be retained and sent to the pathologic examination of specimens, which has become the gold standard for diagnosis of uterine cavity lesions. In patients with a history of IVF-ET failure, hysteroscopy can significantly improve the success rate of reimplantation by treating endometrial polyps, submucosal fibroids, uterine adhesions and other lesions that are suggested during the examination. Therefore, it is recommended that patients with repeated implantation failures should undergo routine hysteroscopic examination to assess the condition of the uterine cavity before re-transplantation, so as to achieve a satisfactory pregnancy rate. The timing of “implantation window” The endometrial implantation window refers to the time when the uterine lining allows the embryo to implant, which is usually around the 20th-24th day of the normal menstrual cycle and lasts for about 24h, and it is the key of embryo implantation to accurately grasp this 24h. However, the implantation window can be advanced, delayed or shortened in about 25% of women due to individual differences. Therefore, the inaccuracy of the endometrial implantation window is one of the most important factors for the failure of embryo implantation. A new individualized exploration of such patients is carried out to understand and control the unique implantation window of the individual at all levels before implantation, and good news has been reported frequently. 3.Uterine perfusion drug therapy For patients with repeated implantation failure, uterine perfusion drug therapy is also often used to improve endometrial tolerance, which has the effect of improving endometrial resistance to estrogen and vasoactive drugs, endometrium with unexplained basal exudate echogenicity, having a therapeutic effect on chronic inflammation of the endometrium, improving the immune status of the endometrium, and promoting endometrial cell proliferation. According to the current statistics of the hospital, this treatment can significantly improve the pregnancy rate of patients with repeated implantation failure. 4, endometrial scraping is a kind of mechanical treatment, on the 3rd-10th day of menstruation, scraping the endometrial walls with a spatula as appropriate, the intrauterine material can be sent to the pathology examination, and it usually does not affect the embryo transfer in the same month. Studies have shown that diagnostic scraping before embryo transfer can significantly increase the embryo implantation rate, pregnancy success rate and live birth rate in patients with repeated implantation failure. The mechanism may be that scraping can remove the irregular hyperplasia of the endothelium, promote blood supply, trigger inflammatory response, etc., thus improving the embryo implantation rate. Changes in endometrial thickness may partially reflect the functional status of the endometrium, thus assessing endometrial tolerance. Although the appropriate endometrial thickness is still debated, there is a consensus that thin endometrium affects embryo implantation. When establishing artificial endometrium for patients with repeated implantation failure, according to the thickness of endometrium and follicular development, estrogen can be added at the right time to improve the development of uterus and promote the growth of endometrium, but the premise is to search for the primary disease and have controversial treatments, such as hysteroscopic treatment, elimination of inflammation, treatment of endocrine etiology, and so on. 6.Chinese medicine auxiliary treatment At present, the introduction of acupuncture, warm ginger moxibustion, mineral salt packs, ultra-short-wave physiotherapy and other appropriate Chinese medicine technology, integrated patient’s physical state to develop a treatment plan to improve the pregnancy rate, improve the patient’s quality of life has a significant therapeutic effect, and some of the patients according to the cause of the implementation of traditional Chinese medicine interventions. To summarize, our aim is “not to give up on any patient”. Improving endometrial tolerance is the key to increase the embryo implantation rate. When facing patients with repeated implantation failures, we should further explore the causes, formulate individualized treatment plans, adjust the patients’ body and mind to the optimal state, and do our best to send little angels to every family.