A 3D display system and a 3D display method are provided. The 3D display system includes a 3D display, a memory, and a processor. The processor is coupled to the 3D display and the memory and is configured to execute the following steps. As a first type application program is executed, an image content of the first type application program is captured, and a stereo format image is generated according to the image content of the first type application program. The stereo format image is delivered to a runtime complying with a specific development standard through an application program interface complying with the specific development standard. A display frame processing associated with the 3D display is performed on the stereo format image through the runtime, and a 3D display image content generated by the display frame processing is provided to the 3D display for displaying.