The invention discloses a backlight membrane material and an LED backlight source. The backlight membrane material comprises an antistatic coating; and a light mixing and diffusion layer for mixing and diffusing light is coated on the antistatic coating. The light mixing and diffusion layer comprises a light mixing layer coated on the antistatic coating and a diffusion layer coated on the light mixing layer, wherein the diffusion layer comprises a resin and diffusion particles which are distributed in the resin and have an refractive index different from that of the light mixing layer. The backlight membrane material has the functions of diffusion and light mixing, namely the function of light mixing is integrated and realized in diffusion fins, and can provide a light mixing distance required by eliminating dark fringes at a seam between light guiding plates in a large-sized liquid crystal device so as to ensure the uniformity of the whole backlight source.