The invention belongs to the field of organic light-emitting diodes, and discloses a preparation method of a top-emitting OLED device with a cathode single-sided grating. The preparation method comprises the following steps: 1) cleaning a substrate and heating the substrate in a vacuum oven; 2) depositing a metal anode on the upper surface of the substrate, then depositing an organic composite layer on the upper surface of the metal anode, and then depositing a metal cathode on the organic composite layer; 3) printing a grating on the upper surface of the prepared metal cathode by using an electrofluid spray printing solution; and 4) enclosing the organic composite layer with epoxy resin, and bonding a glass cover plate with the substrate by using the epoxy resin, thus completing packaging. The top-emitting OLED device with a cathode single-sided grating and the preparation method thereof maintain the excellent electrical conductivity and microcavity effect of a planar device, stimulates the surface plasmon coupling to emit light, so as to greatly improve the light emitting efficiency. The preparation method of the grating can be applied to large-area and array preparation, and isbeneficial to industrial production.