The embodiments of the present invention disclose a color filter substrate, a method for fabricating the same, a display panel and a display device, and relate to the field of display technology, for preventing the occurrence of a color mixture phenomenon of the display device while ensuring that the display device has high aperture ratio and resolution. The color filter substrate comprises a color filter layer which comprises color filter units with at least two colors and distributed in the form of a matrix, and a black matrix is arranged between two adjacent color filter units; the color filter substrate further comprises: light-shielding bulges located at a part of the area of the black matrix and facing towards an incident light direction, for preventing the occurrence of the color mixture among the color filter units with different colors.