1, the residual limb should be appropriate length, the stump should have moderate soft tissue coverage, avoid conical stump, ensure sufficient leverage and good muscle control power. 2.The range of motion of the joints on the amputated side should be normal and powerful. 3.The joints of the residual limb should retain the original physiological function as far as possible, without contracture deformity. 4, the stump should not have pressure pain, bone spurs, neuroma. 5, the skin has no folds, pressure resistance, abrasion resistance, normal sensation, the incision scar is linear, and there is no adhesion with the bones. 6.The stump has been stereotyped.