The invention discloses an LED light box. The LED light box comprises a base plate, a light plate, a side baffle and a light diffusion plate. The light plate is fixed to the base plate through a screw, the edge of the base plate is upwarped, the outer side of the base plate is fixed to the side baffle through a screw, the side baffle is covered with the light diffusion plate, the light diffusion plate comprises a transparent acrylic plate and a printing layer, and one side, close to an internal light source, of the transparent acrylic plate is printed with the printing layer composed of light diffusing agents and varnish mixtures. The TY-383 light diffusing agents adopted in the LED light box play the effects of light adding and light averaging on an advertising lamp box, the TY-383 light diffusing agents and the varnish mixtures are attached to an organic plate of the advertising lamp box by using silk printing technology, and light received by the organic plate is enhanced and evened through the property of the TY-383 light diffusing agents. By the proof of an experiment, reaching the same brightness demand, the light source cost can reduced by 20 percents to 30 percents, and greater economic benefits are created for enterprises.