A spinal fixation aiming device including an arc guide rail； an arc slide unit movably coupled to the arc guide rail； and a tool holder mounted to the arc slide unit and movable to a predetermined position to be selectively fixed at the position. To operate, the arc guide rail is fixed to an operation table and the arc slide unit and the tool holder are adjusted for desired angles for a surgical operation. The adjustment is conducted such that through collaborative combination between the arc guide rail and the arc slide unit, the tool holder is constantly kept corresponding to a spinal fixation nailing site of a patient so as to achieve an effect of easy operation and accurate aiming
