Flat feet, also known as flatfoot syndrome, is a foot deformity in which the foot arch is low or absent due to congenital or postural causes, the affected foot turns out, the foot arch collapses when standing or walking, and symptoms of fatigue or pain occur. Specific symptoms, treatment and prognosis are as follows: The occurrence of flat feet has congenital factors involved such as abnormal development of foot bones, ligaments or muscles, and is also related to acquired factors such as long-term weight-bearing standing, weight gain, improper wearing of shoes, and bone disease of the foot. Early symptoms of flat feet are pain in the medial side of the ankle joint, aggravated by prolonged standing or walking and alleviated by rest. In the later stage, the heel is turned out in the standing position, the inner edge of the foot is full, and the longitudinal arch of the foot is low or disappeared. The treatment of flat feet is mainly based on prevention. Wearing comfortable shoes and socks, avoiding long-term weight-bearing walking, and reducing body weight can help prevent the occurrence of flat feet. Flat feet can be improved by flexing the toes, wearing orthopedic shoes, etc. Patients with severe deformity can have osteotomy with internal displacement of the heel bone. In normal life should pay attention to prevent the occurrence of flat feet, flat feet should go to the hospital in time, with the help of the doctor for regular treatment.