The invention discloses a vacuum infusion liquid level control method and a vacuum infusion device thereof, and the method comprises the steps: 1, placing a
capacitor to be infused into a vacuum main body, and enabling a liquid outlet
pipe of an auxiliary tank body to be communicated with the
capacitor; 2, the vacuum main body and the auxiliary tank body are vacuumized through a
vacuum pump, so that the vacuum main body and the auxiliary tank body have the same negative pressure; 3, the height of the auxiliary tank body is adjusted, so that the upper end face of the overflow
pipe is flush with the planned
perfusion liquid level; 4, liquid to be poured is injected into the auxiliary tank body; step 5, filling until the liquid level in the
capacitor is flush with the upper end face of the overflow
pipe, wherein the liquid level does not change any more to form balance; and 6, closing the valve of the liquid outlet pipe to complete vacuum infusion. According to the vacuum infusion liquid level control method and the vacuum infusion device thereof, the auxiliary tank body with the same negative pressure as the vacuum main body is arranged, the upper end face of the overflow pipe is adjusted to be flush with the planned infusion liquid level face, the vacuum environment metering problem is solved, and the infusion consistency of batch products is guaranteed.