Uterine effusion refers to the presence of some fluid in the uterine cavity, mostly due to acute or chronic endometrial inflammation. The fluid exuded by the inflammation accumulates in the uterine cavity because of partial or complete blockage of the cervix that cannot be drained or is poorly communicated, or it may be physiological if the amount of fluid is small and there are no obvious symptoms. Patients may have no symptoms, or they may show signs of inflammation such as lower abdominal cramps, lumbosacral pain, fever, and elevated white blood cells. If the amount of uterine fluid is small and the patient does not have any discomfort, it can be observed first, and sometimes the fluid can be absorbed on its own. For those who have obvious symptoms, since most of them are caused by endometrial inflammation, anti-inflammatory treatment is necessary, and appropriate antibiotic drugs should be selected according to bacterial culture and drug sensitivity test. At the same time of anti-inflammatory treatment, uterine drainage or hysteroscopy is feasible, and if necessary, diagnostic scraping is performed to understand the nature of uterine fluid, and attention should be paid to keep the uterine drainage open. For infectious diseases should be diagnosed early, active treatment, usually pay attention to sexual hygiene and vulva cleanliness.