A projector includes a light source module, a light guide plate, a polarizing splitter (PBS) module, and a reflection device. The light source module is configured for emitting light. The light guide plate includes a light incident surface, a light output surface, and a light reflection surface. The light source is aligned with the light incident surface. The PBS module includes a polarizing splitter and a LCOS panel. The polarizing splitter is aligned with the light output surface and includes a first mounting surface and a second mounting surface. The polarizing splitter reflects s-polarization light and allows p-polarization light to pass therethrough. The LCOS panel on the second mounting surface modulates the s-polarization light into light with display information signal and reflects the light with display information signal to a projection lens. The reflection device on the first mounting surface reflects the p-polarization light into the projection lens for projection.