The primary objective of the present invention is to provide a method for manufacturing organic layers of organic light-emitting device by using deposition machine, which mainly uses the way of premixing organic materials to dissolving and mixing multi kinds of organic materials; moreover, after completing the vacuum drying process to the mixed organic materials, the method is then proceeded for depositing the mixed organic materials on a substrate in single vapor deposition process; after then, the method is proceeded for ended the deposition process to the material carrier and repeatedly operating deposition process to another material container, so as to produce multi-layers structure on the substrate; wherein method proposed by the present invention can replace the conventional manufacturing process and can avoid the disadvantages thereof.