A liquid transfer apparatus and a control method thereof are provided. The liquid transfer apparatus includes a first auxiliary cover, a second auxiliary cover, a transfer tube and a breathing pipe. The first auxiliary cover is configured to cover a container for holding a liquid to be transferred; and the second auxiliary cover is configured to cover a target container. One end of the transfer tube runs through the first auxiliary cover and the other end runs through the second auxiliary cover. One end of the breathing pipe runs through the first auxiliary cover and the other end is configured to introduce nitrogen, or an inert gas, so that the liquid in the container for holding the liquid to be transferred can be transferred to the target container through the transfer tube.