A fixing mechanism includes a positioning frame for mounting a data access device thereto and including two opposite sidewalls each having two spaced-apart through holes, a plurality of shockproof elements each extending through and being retained in a respective through hole and including a passage, and two positioning rods for positioning the data access device therebetween. The passages of the shockproof elements are adapted to correspond in position with the positioning holes. Each positioning rod includes a main body portion, and two insert portions formed respectively at two opposite ends of the main body portion. Each insert portion extends through the passage of one of the shockproof elements, and is adapted to extend into a respective positioning hole. The shockproof elements are adapted to abut against the data access device when the data access device is positioned between the positioning rods.