A substrate and a display device are provided. A first film layer of the substrate is formed on a third film layer and patterned to form a target pattern. A second film layer is formed on the third film layer and the first film layer. Within a distribution area of the target pattern, film edges of the first film layer are formed with protrusion structures facing the second film layer. Based on the protrusion structures, a deformable margin of the first film layer and the second film layer at a stacking position is increased, and a pattern of the second film layer is thus prevented from being cracked to generate cracks.