For early-stage endometrial cancer, ultrasound is difficult to perform to rule out. For mid- to late-stage endometrial cancer, ultrasound can be an important tool for screening, but cannot confirm or exclude the presence of endometrial cancer. This is because endometrial cancer often lacks characteristic sonographic manifestations. Moreover, the clarity of the sonogram is related to the thickness of the subcutaneous fat of the subject and the degree of gas interference in the intestine. Only when the endometrium can be clearly displayed, the morphological changes of endometrium can be observed, and then the location and depth of the lesion can be determined, which can have important clinical significance for the diagnosis and treatment of endometrial cancer. In early stage of endometrial cancer, the size of uterus is usually normal, the echogenicity at the grassroots level is also uniform, and the boundary with endometrium is also clear, so ultrasound is not very significant in the examination of early stage of endometrial cancer. However, as the cancerous tissues continue to increase, in the middle and late stages of endometrial cancer, the myometrium is eroded and the endometrium undergoes morphological changes. At this time, b ultrasound examination is of great significance to the clinical staging of endometrial cancer as well as the selection of surgical methods and the judgment of prognosis. The diagnosis of early endometrial cancer and relatively small lesions mainly relies on diagnostic scraping, which is difficult to be ruled out by ultrasound, but for middle and late stage endometrial cancer, ultrasound is of great significance.