Physiological ovarian cysts under ultrasound mainly show the following aspects: First, the cysts are relatively small, usually less than 5 cm. If they are larger than 5 cm, there is a possibility of pathological cysts or cysts rupture, torsion and other acute abdominal conditions, and attention must be paid to regular observation and no strenuous activities. Secondly, the cyst has a small amount of punctate blood flow signal or no obvious blood flow signal. Third, the cyst has very good sound transmission, which mostly suggests that the components inside the cyst are all liquid, such as transparent liquid. Fourth, physiological cysts mostly occur in the luteal phase which is after ovulation, mostly formed by follicular luteinization. If the ovarian cysts appear in the follicular phase just after menstruation, they are mostly pathological ovarian cysts, and when ovarian cysts are regularly observed in the clinic, patients are advised to have ultrasound review at the end of menstruation.