The invention relates to an anti-counterfeiting paper additive and a preparation method thereof. The additive has at least two areas having different luminescent characteristics, and the geometrical shapes or sizes of the areas, having the different luminescent characteristics, of the additive have randomness. The areas, having the different luminescent characteristics, of the additive emit electromagnetic waves of different wavelengths when being excited by electromagnetic waves having the same wavelength, and emit electromagnetic waves of same wavelength or different wavelengths when being excited by electromagnetic waves having the different wavelengths. The additive is compounded into paper in a papermaking process.