A light source device includes a first light source, a second light source, a reflective assembly, and a condensing lens defining an optical axis. The first light source includes a first lamp and a first reflector reflecting light beams generated by the first lamp as first parallel light beams. The second light source includes a second lamp and a second reflector reflecting light beams generated by the second lamp. The first light source, the reflective assembly and the condensing lens are arranged in order along the optical axis. The second light source corresponds to the reflective assembly deviated from the optical axis. The reflective assembly reflects light beams reflected by the first reflector back to the first reflector, and reflects light beams from the second reflector to the condensing lens. The condensing lens condenses the first parallel light beams and the light beams reflected by the reflective assembly.