A high-arched foot orthosis adapted to be applied onto lower limbs of a human body, and comprising: two bodies , each one of the two bodies having a wearing space formed inside the body ; a foot portion having a sole located on a bottom of the foot portion ; an instep located on a top of the foot portion ; an arch located on one of two vertical sides of the foot portion , facing the other one of the two bodies , and connected to the sole and the instep ; and a lateral side located on the other one of the two vertical sides of the foot portion , and connected to the sole and the instep ; an ankle portion connected to the foot portion ; a shank portion connected to the ankle portion ; a substrate surrounding the wearing space and extending from the foot portion to the shank portion through the ankle portion ; and an elastomer disposed adjacent to the substrate and surrounding the wearing space, and when in use, extending from the instep of the foot portion at a cuneiform bone (E) of a wearer through the arch and the sole in order, wrapping over a cuboid bone (A) of the wearer , extending through the ankle portion inwardly and upwardly toward the shank portion , and wrapping over a talus bone (C) of the wearer ; and characterized in that each one of the two bodies has a knee portion connected to the shank portion ; and a thigh portion connected to the knee portion ; wherein the elastomer of each one of the two bodies extends to the thigh portion through a rear side of the shank portion , obliquely extends in combination with upward and outward turns through an outer side of the knee portion toward a front side of the thigh portion , and surrounds and fetters the thigh portion . two bodies , each one of the two bodies having a wearing space formed inside the body ; a foot portion having a sole located on a bottom of the foot portion ; an instep located on a top of the foot portion ; an arch located on one of two vertical sides of the foot portion , facing the other one of the two bodies , and connected to the sole and the instep ; and a lateral side located on the other one of the two vertical sides of the foot portion , and connected to the sole and the instep ; an ankle portion connected to the foot portion ; a shank portion connected to the ankle portion ; a substrate surrounding the wearing space and extending from the foot portion to the shank portion through the ankle portion ; and an elastomer disposed adjacent to the substrate and surrounding the wearing space, and when in use, extending from the instep of the foot portion at a cuneiform bone (E) of a wearer through the arch and the sole in order, wrapping over a cuboid bone (A) of the wearer , extending through the ankle portion inwardly and upwardly toward the shank portion , and wrapping over a talus bone (C) of the wearer ; and characterized in that each one of the two bodies has a knee portion connected to the shank portion ; and a thigh portion connected to the knee portion ; a knee portion connected to the shank portion ; and a thigh portion connected to the knee portion ; wherein the elastomer of each one of the two bodies extends to the thigh portion through a rear side of the shank portion , obliquely extends in combination with upward and outward turns through an outer side of the knee portion toward a front side of the thigh portion , and surrounds and fetters the thigh portion . <EOS>