Array substrate, preparation method of array substrate, display panel and display device

The invention provides an array substrate, a preparation method of the array substrate, a display panel and a display device, which belongs to the technical field of BMIess display, and can solve a problem that a conductive light reflecting structure in an existing display panel will affect a display effect and the external visibility. The array substrate provided by the invention comprises a conductive light reflecting structure and a transparent metal oxide layer arranged above the conductive light reflecting structure, wherein the transparent metal oxide layer is provided with metal particles thereon, and the metal particles are formed by gathering metal in the transparent metal oxide layer.