The invention discloses a preparation method of titanium pigment used in ship paint. The method comprises the following steps that: a. metatitanic acid is calcined, such that a titanium pigment crude product is obtained, the titanium pigment crude product is prepared into TiO2 slurry, and sodium hexametaphosphate is added to the slurry; b. the slurry is heated, a silicon-containing compound is added to the slurry, and the slurry is homogenized; c. the pH value of the TiO2 slurry is regulated to 0.8 to 4; d. after the slurry is slaked, an organic dispersant is added to the slurry, an aluminum-containing compound is added to the slurry, and the mixture is homogenized; e. the pH value of the TiO2 slurry is regulated to 4 to 8; f. the TiO2 slurry is slaked; g. the TiO2 slurry is filtered, such that the resistivity of the filter cake is greater than or equal to 100 [omega]M; and the filter cake is dried and heat treated; h. an organic surface conditioning agent is added to the filter cake, and the filter cake is crushed, such that the finished product is obtained. According to the present invention, nano-sized silicon oxide sol and alumina sol are prepared sequentially. Through physical adsorption and chemical absorption, a compact coating layer is formed on the surface of the TiO2 particles. Then, the coating layer is firmly attached to the surface of the TiO2 particles through chemical deposition. With the coating layer, the product provided by the present invention possesses good dispersibility, weatherability and corrosion resistance. Meanwhile, according to the method provided by the present invention, the raw materials are easy to obtain, the processes are smooth and are easy to control.