Transvaginal ultrasound uses a probe with high frequency and good resolution, is close to the pelvic organs, does not require bladder filling, is not disturbed by obesity and gas, and is easier to show the microstructure of endometrial and ovarian lesions than transabdominal ultrasound. Transvaginal ultrasound, as a noninvasive examination method, is easy to perform and reproducible, and has become an important examination method for the auxiliary diagnosis of gynecological diseases. It can suggest a tendentious diagnostic opinion for most uterine lesions such as uterine fibroids, typical adenomyosis, uterine malformations, endometrial polyp-like lesions, uterine adhesions, intrauterine devices, as well as typical uterine malignant lesions and ovarian lesions. For atypical lesions a combination of clinical manifestations, laboratory methods or other imaging methods are needed to further aid the diagnosis. The limitations are that transvaginal ultrasonography is not indicated for women with no sexual history and with vaginal malformations and acute vaginitis, during menstruation, and the depth of transvaginal ultrasound scan is usually 8-10 cm, which makes it difficult to show the full picture of larger pelvic masses or the relationship with adjacent organs. relationship. In this case, a combined transabdominal ultrasound and transvaginal ultrasound scan can give more satisfactory results.