A bi-stable projection screen includes a light diffusion unit and a bi-stable display unit stacked together. The bi-stable display unit, when actuated, selectively operates in a first mode or a second mode. When operating in the first mode (e.g., a transmission mode or a reflection mode), the bi-stable display unit receives a projection light from a front projection or a rear projection, and emits the projection light after modulation. When operating in the second mode (a non-transmission mode or a non-reflection mode), the bi-stable display unit is a pattern to become a part of a scene. The light diffusion unit receives and diffuses the modulated projection light to be perceived by human eyes.