PURPOSE: A body fixing device is provided to reduce the time of wearing by omitting a process of tightening each of conventional nylon string or multiple velcroes and fixing a body with using an external air injection means (aerial pressurizing tank). CONSTITUTION: A body fixing device comprises: a kerf (10) which fixes more than one of the upper limb, pelvic limb and pelvis of the user and supports; a supporting part which is formed on the inner surface of the kerf; an air cell which is supported with the supporting part. The air cell has a first air cell and a second air cell which are separated from each other; and comprises: a first inlet port (131) in which the air is injected from the external air tank to the first air cell the air cell; a second inlet port (132) in which the air is injected to the second air cell; a first vent (141) which ejects the air of the first air cell to the air tank; and a second vent (142) which ejects the air of the second air cell to the air tank.
