Flat feet can be determined by the patient’s symptoms and signs as well as relevant imaging tests such as X-rays. Flat feet refers to a foot deformity in which the arches of the feet are low or absent for various reasons, and the soles of the feet flatten when standing or walking, resulting in fatigue or pain. Under normal circumstances, the sole of the foot is arched, not flat, and consists of two longitudinal arches in the anterior-posterior direction and transverse arches in the internal-external direction, which hold up the sole of the foot. The arch plays an important role in weight bearing, cushioning shock, and protecting plantar nerves and blood vessels from compression. In patients with flat feet, early ankle pain, pain aggravated by prolonged standing or walking, alleviated by rest, if further development, pain aggravated, may be accompanied by gait abnormalities, ankle swelling and so on. The medial side of the foot is fuller and has a larger footprint when standing. After the appearance of these symptoms, it is recommended to go to the orthopedic department of the hospital in time for consultation. Doctors will often determine the existence of flat feet through the foot orthopedic X-ray examination, and if there is doubt in the X-ray examination, further CT examination may be carried out to make a clear diagnosis.