The utility model relates to a radiator fixing device. The radiator fixing device comprises a hook body arranged on a radiator side and a fastener on a printed circuit board side, wherein the fastener is fixed on the printed circuit board in a surface mounting way, an elastic body is sleeved on the hook body, and the hook body is fastened with the fastener through a mounting hole formed on the radiator, and the radiator is mounted and fixed on the printed circuit board. The radiator fixing device avoids the hole from being formed on the printed circuit board, the area of the fixing structure occupying the printed circuit board is effectively reduced, the useful area of the wiring of the printed circuit board is increased, and the design difficulty of the wiring of the printed circuit board is reduced, the structure is simple, and the radiator fixing device is conveniently mounted and reliably connected. For the multi-layer printed circuit board structure, because the fastener is only arranged on the surface of the first layer of the printed circuit board, and the increase degree of the useful area of the wiring of the printed circuit board is higher.