The invention provides a method and device for controlling a pressure difference of a refrigerant shuntingdevice. The method includes the steps that a current working mode of an internal machine is obtained; a working mode switching signal of the internal machine is obtained; and according to the current working mode of the internal machine and the working mode switching signal of the internal machine, the pressure difference of the refrigerant shunting device is controlled. Therefore, according to the current working mode of the internal machine and the working mode switching signal of the internal machine, during switching of the working mode of the internal machine, pressure equalization on the internal machine side is realized to lower the pressure difference corresponding to the two sides of an on-off valve in the refrigerant shuntingdevice, and thus, in the switching process of the working mode of the internal machine, the noise of the refrigerant shuntingdevice switching the on-off valve is reduced or avoided.