An exemplary embodiment of the present invention provides a method for preparing an organic light-emitting device, comprising the steps of: 1) forming a spacer pattern on a first electrode formed on a substrate; 2) forming an organic material layer and a second electrode; 3) exposing the first electrode by forming an encapsulation thin film and then etching at least one portion of the encapsulation thin film; and 4) forming an auxiliary electrode which is electrically connected to the first electrode exposed in the step 3). The organic light-emitting device according to the exemplary embodiment of the present invention may solve problems of a voltage drop due to resistance of a transparent electrode in a longitudinal direction and of resultant brightness non-uniformity of the diode.