The present invention relates to a method for preparing an organic light-emitting diode, including: (A) providing a substrate with a first electrode thereon; (B) using a first solution to form a first light-emitting layer over the first electrode, where the first solution includes a first solvent and a first dye; (C) using a second solution to form a second light-emitting layer over the first light-emitting layer, where the second solution includes a second solvent and a second dye, and the first solvent and the second solvent are different solvents and satisfy at least one of the following conditions: the dipole moment difference between the first solvent and the second solvent being 0.5 D or more, or the viscosity of the first solvent being 0.3 mPas or more; and (D) forming a second electrode over the second light-emitting layer. |