A projector includes a projection lens set, a digital micro-mirror device, a prism unit, a light merging unit, a light guide unit, and a light source device. The light source device includes a laser light source and a color wheel. The laser light source is positioned in a straight optical path and generates a first light. The color wheel is positioned in the straight optical path. The first light irradiates the color wheel to generate a second light and the third light. The light merging unit merges the first, second, and third lights to generate a mixed light. The light guide unit guides the mixed light to the prism unit. The mixed light is refracted to the DMD via the prism unit, and then the refracted mixed light is reflected to the projection lens set via the DMD.