A three-dimensional (3D) display system is provided. The 3D display system includes a backlight plate, a display panel, a light-splitting device, and a polarization state controller. The display panel is configured to display a two-dimensional (2D) image in a 2D mode or to display a 3D image in a 3D mode. The light-splitting device is configured to an arrangement module configured to pass the 2D image in the 2D mode, and to separate the 3D image into a left image and a right image. Further, the polarization state controller is disposed between the display panel and the light-splitting device and is configured to rotate a polarization direction of light emitted from the display panel in the 2D mode, and to keep the polarization direction of the light emitted from the display panel in the 3D mode.