The centrifuge uses the elastic force of metal spring to drive the horizontal bar to rotate through the central shaft to generate centrifugal force. One end of the horizontal bar is provided with a crucible and a support for fixing the mold, and the other end is equipped with a metal mound for balancing. Before casting, loosen the central screw on the horizontal bar and fix a mold on the bracket. After adjusting the balance, tighten the screw and remove the mold. Then rotate the horizontal rod clockwise for about 3-5 turns to tighten the spring, and then lift the jack post to fix the horizontal bar temporarily. During casting, the casting alloy is placed in the crucible, and then the roasted mold is fixed on the bracket. The opening of the casting mold is facing the crucible hole. The device with flame is used to heat the casting gold, and the alloy is fully melted. At this time, the left hand supports the metal mound of the horizontal bar, and gently moves the horizontal bar to make the kilogram column fall down. At the same time, the flame is turned away. Due to the spring force of the horizontal bar, it rapidly rotates in the counter clockwise direction, and the molten gold in the crucible is thrown into the mold cavity under the action of centrifugal force to complete the casting.