The invention discloses a fixing device used on the arm of a bone fracture patient. The fixing device comprises a fixing frame, wherein multiple fixing mechanisms are arranged on two sides of the fixing frame, each fixing mechanism is provided with a groove, a small fixing bearing, a rotary shaft, a clockwork spring, a belt take-up wheel, a fixing belt, a stop block, a rectangular clamping piece and a rectangular clamping groove. A protective massaging mechanism is arranged in the fixing frame and is provided with an arc-shaped protective plate, a protective sponge cushion, a hook-and-loop fastener belt hook face, a hook-and-loop fastener belt loop face, a low-frequency pulser, a microcomputer, an electrode piece, an extensible pyromagnetic contact and a silica gel gasket, a hanging structure is arranged on the fixing frame, an auxiliary mechanism is arranged on the fixing frame and is provided with a containing box, a blocking door mechanism, a foldable waterproof raincoat, a waterproof air cushion, a red warning lamp, a GPS positioner, a one-key alarm apparatus, a protective box, a protective mechanism and a small rechargeable lithium battery, and a controller is arranged on thelower surface of the fixing frame. The fixing device has the advantages of being simple in structure and good in practicability.