The normal thickness of the uterus is 2 to 3 cm. The uterus is the organ that nurtures the embryo, fetus and produces menstruation. The uterus has a capacity of about 5ml and a thickness of 2~3cm. The uterus is divided into two parts, the body and the neck, of which the endometrium in the body part of the uterus undergoes cyclic changes with menstrual changes. The endometrial thickness increases from 0.5mm to 3~5mm during the proliferative phase of menstruation, and the endometrium thickens to 10mm during the late secretory phase. The thinning or thickening of the thickness of the uterus is related to certain diseases, such as polycystic ovary syndrome, scraping the uterus will lead to thinning of the uterus, uterine fibroids, endometrial inflammation and so on will lead to the thickening of the endometrium. Regular checkups for timely detection of uterine diseases and timely treatment improves the quality of life.