The present disclosure provides a gray scale setting method, a display substrate and a display apparatus, and relates to the field of display technology. The gray scale setting method of the present disclosure applied to a display substrate. The display substrate has a display area and a non-display area. The display substrate includes an edge pixel on a boundary between the display area and the non-display area, and the edge pixel includes a first sub-area pixel within the display area and a second sub-area pixel within the non-display area. The method includes: acquiring an area ratio of the first sub-area relative to the edge pixel; determining a relative transmittance of the edge pixel according to the area ratio of the first sub-area relative to the edge pixel; and determining a display gray scale for the edge pixel according to the determined relative transmittance.