The invention relates to a preparation method of a high-weather-resistance and high-dispersion plastic color master batch titanium dioxide pigment, and the method comprises the following steps: producing a titanium dioxide primary product by a chlorination process, pulping in desalted water to prepare a slurry, regulating the pH value with an inorganic acid or alkali, dispersing, and grinding; heating the slurry, adding an alkaline aluminate compound, and simultaneously maintaining the pH value constant by using inorganic acid or an acidic aluminum compound to form an inorganic aluminum film coating layer on the surface of titanium dioxide particles; adjusting the pH value by adopting an inorganic alkali solution, and adding a polysiloxane liquid containing an active group to form an organic silicon film coating layer; filtering with deionized water, washing, and drying; adding a citrate ester organic treating agent in the steam-pulverizing process, and performing steam-pulverizing treatment to obtain a titanium dioxide finished product. The advantages are that: the titanium dioxide pigment prepared by the method has high weather resistance, high whiteness, high covering power andexcellent dispersion processability, has low dust flying in the production and use processes, is environment-friendly, and is suitable for the application fields of high-end color master batches suchas polyolefin, engineering plastics and the like