The invention discloses an organic light emitting device, which comprises an anode, a first organic function layer, a light emitting layer, a second organic function layer and a cathode, wherein the first organic function layer is formed on the anode; the light emitting layer is formed on the first organic function layer; the second organic function layer is formed on the light emitting layer; thecathode is formed on the second organic function layer; the light emitting layer comprises a red light emitting layer, a green light emitting layer and a blue light emitting layer, the thickness of the red light emitting layer is larger than that of the green light emitting layer, and the thickness of the red light emitting layer is larger than that of the blue light emitting layer. Through enabling the thickness of the red light emitting layer to be larger than those of the green light emitting layer and the blue light emitting layer at the same time, the increased red light emitting layer can be used as a partial optical compensation layer of the red light emitting layer, and the problem that MASK blocking is easy to lead to the reduction of the yield of the organic light emitting device when a precise MASK is adopted to evaporate the optical compensation layer can be effectively solved.