Flat foot is a common foot deformity。It is a physiological state in the early stage of infants and young children, and some children""s foot arches will gradually develop as they grow. But some children develop clinical symptoms and their deformities will Continue to exist until adulthood. According to the existence of medial longitudinal arch under non-weight-bearing condition, flatfoot can be divided into flexible flatfoot and rigid flatfoot. As parents pay more and more attention to the disease in recent years, more and more children with flexible flatfoot can be diagnosed at an early stage and seek for treatment. Orthotic Insole therapy is often the first choice for children with flexible flatfoot. This paper will sort out the recent research status and shortcomings of Orthotic Insole in the treatment of children""s flexible flatfoot, and Look forward to the future development of this field.