The endometrium is thin, so we should find out the reason and deal with it well. Thin endometrium is common in organic diseases, and it is more common in endometrial damage after abortion and curettage, which leads to thinning of endometrium and reduction of menstrual flow. In this case, it is often very effective to give estrogen cycle replacement therapy and use a slightly larger dose of hormone to promote the proliferation of endometrial cells. Some patients are caused by dense adhesion of uterine cavity, which is very difficult to deal with. It can be treated under hysteroscopy, but the effect is not good. Thin endometrium is sometimes seen in functional diseases, such as polycystic ovary syndrome, hyperprolactinemia and other endocrine diseases, and sometimes thin endometrium is seen, which requires specific endocrine treatment.