Objective To study the effect from different structures and material hardness of orthopedic insoles on flatfoot correction. Methods The contours of flatfoot under weight-bearing and non-weight-bearing conditions were scanned by Infoot system. The 3 kinds of medial longitudinal arch height (typeⅠ, Ⅱ, Ⅲ) and 3 kinds of material hardness (30°, 35°, 42°) from orthopedic insoles were used to compare their effects on flatfoot by the embedded insole test system. Results TypeⅠorthopedic insoles could significantly restore the anatomical position by improving the height of navicular bone, and redistribute the concentrated plantar pressure and increase the loading area of medial longitudinal arch with material hardness of 35°. Conclusions The appropriate insole shows a favorable orthopedic effect to ameliorate the foot deformity of flatfoot patients. The research findings lay a theoretical basis on design of the personalized orthopedic insoles.