An organic light-emitting device proposes a primary pixel including one or more first subpixel, second subpixel, and third subpixel. The first subpixel is a white subpixel. The second subpixel includes the first light-emitting material for synthesizing the white light. The third subpixel includes the second light-emitting material. The organic light-emitting device further includes a third light-emitting material. The material for the second subpixel includes an original color zone and a synthesized color zone. The first light-emitting material for synthesizing the white light corresponding to the synthesized color zone. The transmission distance of the excitons produced by the second light-emitting material is smaller than the thickness of the function layer with the second light-emitting material. By using the organic light-emitting device, the brightness and color saturation of an image is well improved, power consumes less, and the lifespan of the organic light-emitting device is prolonged.