The present disclosure provides a driving substrate, a method for preparing the same, and a flexible display device. The driving substrate includes: a base substrate; a stress buffer layer located on the base substrate; a wiring structure located on a surface of the stress buffer layer away from the base substrate, a thickness of a wiring of the wiring structure in contact with the stress buffer layer being greater than a threshold; a first insulating layer located on a surface of the wiring structure away from the base substrate; a plurality of electronic components on a surface of the first insulating layer away from the base substrate; the electronic component being connected to the wiring structure through a via hole penetrating the first insulating layer.