Abstract: A length-adjustable pelvis-locking belt which is tightly wound around portions immediately under the front upper spines of both iliums and a body side at the sacrum position. The belt comprises hard pressing mechanisms which are positioned at both parts corresponding to the spines and the femur trochanter major in the belt to inwardly press the body side between the spines and the femur trochanter major. The belt comprises a plurality of fastening belts which can be adjusted in length and connected to each other by means of connecting members. The pressing mechanism comprises a plurality of hard pressing members hinged foldably to each other.