1. A method for manufacturing an organic light-emitting device (OLED) pixel structure, comprising steps of: providing a substrate; forming a plurality of thin-film transistors on the substrate; defining a plurality of deposited regions on the plurality of thin-film transistors; and evaporating an organic electro-luminescent (EL) material through an opening of a shadow mask onto at least two of the deposited regions, wherein each of the deposited regions with the evaporated organic electro-luminescent material is equally divided into a plurality of sub-pixels, each sub-pixel respectively corresponding to a pixel, an arrangement of the sub-pixels in two immediately adjacent pixels being different, wherein the colors of any two immediately adjacent sub-pixels that respectively correspond to any two immediately adjacent pixels are the same.