A manufacturing method of an organic light emitting display device is disclosed which includes: forming a thin film transistor on each sub-pixel region which is defined in a substrate; forming a passivation layer on the substrate provided with the thin film transistor; forming a first electrode of an organic light emitting diode in each sub-pixel region of the passivation layer; forming a bank pattern in boundaries of the sub-pixel region of the passivation layer; forming a photoresist pattern, which exposes a first sub-pixel region, on the bank pattern; forming an organic light emission layer on the first electrode within the first sub-pixel region and an organic material layer on the photoresist pattern by depositing an organic material on the entire surface of the substrate provided with the photoresist pattern; and removing the photoresist pattern and the organic material pattern using a detachment film.