A dual screen point-of-sale system includes a point-of-sale device and a tablet computer. The point-of-sale device includes a first display screen and a first connection part. A first picture of the point-of-sale device is shown on the first display screen in response to a first device signal. The first connection part receives the first device signal. The tablet computer includes a second connection part and a second display screen. When the first connection part and the first connection part are in communication with each other, the first device signal is transmitted from the point-of-sale device to the tablet computer. Consequently, a picture corresponding to the first device signal is shown on the second display screen. When the first connection part and the first connection part are not in communication with each other, a second picture is shown on the second display screen.