The invention discloses a PET (polyethylene terephthalate) base material used for a filter membrane, a preparation method as well as the filter membrane and a plasma display screen comprising the PET base material. The PET base material comprises one or more of inorganic pigment, organic pigment and dye, wherein the inorganic pigment is one or more of metallic oxide, sulfide, sulfate, chromate and carbon black; the organic pigment is one or more of azo pigment, phthalocyanine pigment, heterocyclic pigment, lake pigment and fluorescent pigment; and the dye is one or more of pyrazolone derivative, quinophthalone, fluorescent polycyclic ring dye, naphthazarin, benzopyrone, azo, fluorescent reactive dye, anthraquinone reactive dye, picene ketone dye, anthraquinone reactive derivative, fluorescent polycyclic ring and polymethylene dye. A material with a toning function is added into the PET base material, thus the phenomenon that chemical substances in pressure-sensitive adhesive (PSA) react with the material with the toning function to generate the discoloration is avoided, and meanwhile, the plasma screen capable of improving color is obtained.