The invention provides an array substrate, a preparation method thereof and a display device and relates to the technical field of display. ESD (electronic static discharge) produced through induction after static electricity accumulated on equipment is contacted with the back of a substrate body of the array substrate can be prevented from being transmitted to signal lines in the array substrate and/or TFT elements, and the yield of products is increased. The preparation method comprises steps as follows: the step of forming a grid line, a data line and a film transistor above the substrate body and the step of sequentially forming a static shielding layer and an isolation layer covering the static shielding layer on the substrate body before the preceding step, wherein the orthographic projection of patterns of the static shielding layer on the substrate body covers the orthographic projection of the pattern of at least one of the grid line, the data line and the film transistor which remain to be formed on the substrate body. The method is used for preparation of the array substrate and the display device comprising the array substrate.