Embodiments of the present disclosure provide a color filter substrate, a manufacturing method thereof, and a display device. The color filter substrate includes a substrate, color blocks, and light shielding portions positioned on the substrate. The color blocks and the light shielding portions are alternately arranged along a first direction. A size of the light shielding portions along the first direction depends on a sensitivity of human eyes to a mixture of colors, which are different, of the color blocks on both sides of each of the light shielding portions.