An augmented reality screen system includes an augmented reality device and a host. The augmented reality device is configured to take a physical mark through a camera. The host is configured to receive the physical mark, determine position information and rotation information of the physical mark, and fetch a virtual image from a storage device through a processor of the host. The processor transmits an adjusted virtual image to the augmented reality device according to the position information and the rotation information, and the augmentation device projects the adjusted virtual image to a display of the augmented reality device. The adjusted virtual image becomes a virtual extended screen, and the virtual extended screen and the physical mark are simultaneously displayed on the display of the augmented reality device.