The utility model discloses a fracture external fixing device. The device comprises an inner layer and an outer layer. The outer layer is in a tube shape and detachable. The device is characterized in that flexible film gel injection air bags are arranged on the inner layer and comprise two independent air bags with gel injection holes, and the ends of the two independent air bags are connected through a middle closing seal to form an elongated soft air bag. The elongated soft air bag closing connection position is disposed on one side of the fracture position and covers the whole fracture limb. The two tail ends of the elongated soft air bag are connected to be disposed on the opposite side of the closing connection position. The outer layer covers and fixes the inner layer and clamps the surplus air bag portions of the two tail ends of the elongated soft air bag on the outside of the outer layer. Thermoplastic elastomers or medical silicon are injected into the independent air bags through the gel injection holes to form two inner elastic fixing elements attached to the fracture position in space between the outer layer and the fracture position.