An elastic compressor for a pelvic band has an inner belt and an outer belt. The inner belt has a first end, a second end, an inner surface and two male fasteners. The male fasteners are mounted on the inner surface and are located adjacent respectively to the first end and the second end. The outer belt is attached to the inner belt and has a first end, a second end, an inner surface and a male fastener. The male fastener is mounted on the inner surface adjacent to the first end. After a user wear a pelvic band on the pelvis, the user can attach the male fastener of the inner belt and the male fastener of the outer belt to the pelvic band.