Projection device and light source system and projection method thereof

The invention discloses a projection device and a light source system and projection method thereof. The projection method comprises the steps of controlling part of the light-emitting units to provide light beams to serve as first light beams; detecting whether characteristic parameters of the light-emitting units providing the light beams reach a preset value or not; when the characteristic parameters of the light-emitting units providing the light beams do not reach the preset value, disabling the light-emitting units providing the light beams, and controlling the rest light-emitting unitsto provide standby light beams to serve as the first light beams; converting part of the first light beams into second light beams; converging the second light beams and the first light beams withoutbeing subjected to wavelength conversion to generate an illumination light beam; converting the illumination light beam into an image light beam; and converting the image light beam into a projectionlight beam. According to th