The present invention discloses a cuff which includes a wrap band. A surface of the wrap band is provided respectively with a first Velcro strip and a second Velcro strip made of a different material than the first Velcro strip that the first Velcro strip and the second Velcro strip can be fastened and fixed together. An interior of the wrap band is provided with a bladder which is connected with more than one joint pipe. The joint pipes are connected with a pressure regulation device by which a pressure of the bladder is increased and decreased repeatedly to result in a volume change that wounded tissues and surrounding unwounded tissues are depressurized and pressurized, thereby achieving an effect of reducing a risk of necrosis to the wounded tissues and the surrounding unwounded tissues.