A projection system, comprising a light modulation device, a light source system and a light offset device. The light source system is used for emitting one or more illumination sub-beams. The light modulation device is used for modulating illumination light according to image data to form image light, the image light being used for displaying an image corresponding to the image data. The light offset device is used for transferring one illumination sub-beam to each zone of a micro-mirror unit by means of a time sequence such that the micro-mirror unit modulates the illumination sub-beam by means of a time sequence to form image light of a pixel corresponding to each zone, wherein each zone corresponds to one pixel of an image.