A mono-panel projector having a light source device of laser LED is provided with at least one laser LED light source, at least one light magnifying element, a cross type color filter, a light guiding element, a prism module, a digital micromirror device, and a projecting lens module. The laser LED light source generates three small-diameter laser beams of red, green, and blue primary colors all of which are magnified by the light magnifying element, and concentrated into a composite laser beam by the cross type color filter. After that, the composite laser beam is guided by the light guiding element, and projected to the digital micromirror device via the prism module for generating images on the digital micromirror device. Then, the images are reflected to the projecting lens module followed by projecting out of the projecting lens module so that the projector of the present invention provides higher resolution, higher sharpness, brighter images, and higher color saturation by the laser LED light source while providing advantages of minimizing volume, lowering power consumption, enhancing reaction speed, elongating life time, and increasing power efficiency.