A spherical core spraying tool comprises a spraying spindle and connecting rods; the spraying spindle is circumferentially provided with a plurality of protruding rings, and is axially provided with a strip-shaped groove; the connecting rods are disposed in the groove; one end of the spraying spindle is a power input end, and the other end is provided with a locking sleeve; the groove runs through the protruding rings. By spot-welding steel balls in an inner hole of a spherical core and fitting the spherical core over the spraying spindle, the steel balls are stuck in the groove of the spraying spindle, and the both sides of the steel balls are tightened by means of the connecting rods in abutting-against fashion, so that a plurality of spherical cores is fixed together with the spraying spindle, and the plurality of spherical cores can be spray-coated simultaneously, thereby improving the efficiency.