Disclosed is an insole capable of improving lower limb health of middle-aged and aged people. The insole comprises an insole body, and is characterized in that the upper side of the front sole of the insole body is an inclined face which inclines towards the inner side of the sole of a foot, and the middle portion of the insole body is provided with a supporting mechanism which is corresponding to an arch of the foot. A through hole is formed in a position, which is corresponding to a root bone of a heel, of the insole body, and soft materials are embedded in the through hole. The insole has the advantages that range that a crus inclines outwards is reduced by the inclined face which is high in exterior and low in interior on the insole, foot sprain can be prevented, stress of knee-joint is changed, and lesion of arthritis can be relieved. Sliding of the sole of the foot can be prevented due to the anti-sliding lines on the inclined face. Squeezing of the insole to heel of the foot can be relieved through the soft materials in the heel portion of the insole, and pains of heel fasciitis of the middle-aged and aged people can be reduced effectively. Collapse of arches of feet of the middle-aged and aged people can be relieved effectively through the arch massage function and the supporting function of the supporting mechanism of the arch on the middle portion of the insole. The lower limb health of the middle-aged and aged people can be improved by the integrative action above.