Abstract: A vacuum die casting method may include: coupling a fixed die and a movable die to each other; closing a molten metal pouring hole formed in a sleeve using an injection plunger operated in the sleeve, which is formed on a lower side of the fixed die or the movable die; performing vacuum decompression in a cavity formed between the fixed die and the movable die using a vacuum decompression device connected to chill vent blocks provided on upper portions of the fixed die and the movable die; supplying oxygen in the cavity using an oxygen supply device connected to the chill vent blocks after completing the step of performing vacuum decompression; and supplying a molten metal to the cavity through the molten metal pouring hole.