Preparation methods for a pixel defining layer and an OLED, a pixel defining element, an OLED, and a display device are disclosed. The method for preparing a pixel defining layer comprises: providing a substrate; forming a first defining pattern on the substrate, wherein the first defining pattern is composed of a concave accommodation groove, and the concave accommodation groove is formed by ink jet printing a first material, forming a first defining pattern layer in a predetermined region of the substrate, and then subjecting the first defining pattern layer to a drying treatment; forming a second defining pattern by ink jet printing a second material in the concave accommodation groove, wherein the first defining pattern and the second defining pattern constitute the pixel defining layer.