The invention discloses an automatic switching device for intelligently controlling parallel operation of 110kV three-winding transformers. The device comprises a current detecting and transforming circuit and a current judging and processing circuit, wherein the current detecting and transforming circuit is connected on the high-voltage side of a first transformer in series; the signal output end of the current detecting and transforming circuit is connected with the signal input end of the current judging and processing circuit; the signal output end of the current judging and processing circuit is connected with a transformer inputting and closing circuit, a transformer quitting and opening circuit, a high-voltage side neutral point isolating switch closing circuit and a high-voltage side neutral point isolating switch opening circuit respectively; the transformer inputting and closing circuit comprises a high-voltage side inputting and closing circuit, a low-voltage side inputting and closing circuit and a medium-voltage side inputting and closing circuit; and the transformer quitting and opening circuit comprises a high-voltage side quitting and opening circuit, a low-voltage side quitting and opening circuit and a medium-voltage side quitting and opening circuit. The device can reduce the labor intensity and improve the safe reliability of transformer operation.