Preparation method of display panel and display panel

The invention provides a preparation method of a display panel and the display panel. The preparation method comprises the following steps: preparing a substrate; a pixel circuit layer is formed on one side of the substrate, the pixel circuit layer comprises a driving transistor and a switching transistor, the driving transistor and the switching transistor are processed by adopting a high-temperature annealing process, and the annealing temperature of the driving transistor is higher than that of the switching transistor; and forming a light-emitting structure layer on one side, deviating from the substrate, of the pixel circuit layer. The preparation method of the display panel is simple in process and convenient to operate, the characteristics of different thin film transistors can be adjusted in one manufacturing process, the switching speed of the switching transistor is increased, meanwhile, the gray scale resolution capability of the driving transistor is enhanced, and then the display performance of t