The present invention discloses an organic light emitting diode and a manufacturing method thereof. The OLED comprises a first electrode, a first hole-transporting layer disposed on the first electrode, a second hole-transporting layer disposed on the first hole-transporting layer, a first light-emitting layer disposed on the second hole-transporting layer, an electron-transporting layer disposed on the first light-emitting layer, an electron injection layer disposed on the electron-transporting layer and a second electrode disposed on the electron injection layer. The energy level of the first light-emitting layer in the lowest unoccupied molecular orbital is lower than that of the second hole-transporting layer, and the thickness of the first hole-transporting layer is larger than that of the second hole-transporting layer. |