The present invention provides a color film substrate and display device. The color film substrate comprises a bottom substrate; a black matrix disposed on the bottom substrate and a plurality of opening areas arranged in matrix at intervals are formed in the black matrix to be sub-pixel areas of the color film substrate; and a first conversion material layer formed within a first sub-pixel area of the sub-pixel areas, wherein the first conversion material layer converts an incident light with a first wavelength into a first emitting light with a second wavelength, and the first wavelength is greater than the second wavelength. The performance and lifetime of a display panel can be improved by this technique solution.