The invention discloses a preparation method of high-dispersion and fine-grain-size white ceramic ink powder. The preparation method comprises the steps that a ZrOCl2 water solution with the concentration being 0.05-0.3mol/l is prepared; a Mg(NO3)2 water solution with the concentration being 0.05-0.3mol/l is prepared; the Mg(NO3)2 water solution is added into the same volume of the ZrOCl2 water solution; the mixed water solution of Mg(NO3)2 and ZrOCl2 is stirred through a stirring machine, the stirring speed is 200-300r/min, and stirring is conducted for 5-8 minutes till the mixed water solution is stirred to be even; polyethylene wax is added into the even mixed liquid, wherein the mass of polyethylene wax is 1-1.5% of Mg(NO3)2; ammonium hydroxide is added into the solution mixed with polyethylene wax, the PH value is controlled to be between 10 and 11, the water solution is heated, and the water temperature is controlled to be 80-90 DEG C and maintained for 3-4 hours till precipitateis separated out; the water solution with the precipitate is poured out to be subjected to vacuum filtration, and the surface of the precipitate is washed with acetone for 2-3 times; the washed precipitate is placed into a drying oven to be dried, wherein the temperature of the drying oven is 80-90 DEG C; and the dried precipitate is subjected to thermal treatment, and then grinded, and MgO-ZrO2ceramic ink powder is obtained. The color of ceramic ink is enriched, the preparation method of the white ceramic ink is enriched as well, and the technology is simple.