A vaginal ultrasound is an examination of the uterus, ovaries, and pelvis, the internal genitalia of a woman who is sexually active. Ultrasound is a type of gynecological ultrasound that refers to the use of the physical properties of ultrasound through the vaginal route in order to understand the patient’s internal genitalia. Ultrasound is often used for early pregnancy, early-mid pregnancy screening, ectopic pregnancy, identification and diagnosis of benign and malignant tumors of the uterus and ovaries, etc. It reflects the pathological and physiological changes in the uterus, ovaries, pelvis and other parts of the body. Ultrasound through the vagina, usually less susceptible to obesity, abdominal distension and other ultrasound adverse factors, clearer than the transabdominal gynecological ultrasound. Teenage women who are not sexually active and those who are in the late stages of pregnancy do not usually undergo a vaginal ultrasound.