A display substrate, a manufacturing method of the display substrate and a display device are provided. The display substrate includes a plurality of sub-pixels arranged in an array in a display area. The display area includes a boundary extending in non-straight line. The plurality of sub-pixels arranged in the array include a plurality of first sub-pixels whose distances to the boundary extending in non-straight line are less than a preset threshold and a plurality of second sub-pixels other than the plurality of first sub-pixels, where at least one of the first sub-pixels is smaller in area than each of the second sub-pixels.