The invention discloses a preparing method for coloring zirconium oxide powder and a preparing method for multilayer and multicolor dental ceramics. The preparing method comprises the steps that 1, salt colorant of soluble rare earth is dissolved into water, or ethyl alcohol or mixed liquor of the water and ethyl alcohol, high-transparency or medium-transparency or low-transparency dental zirconium oxide powder is added, and the mixture is stirred and poured into a baking disc; 2, the baking disc is placed in a shady and cool place and dried to obtain dry powder; 3, ball milling is carried out, and screening is carried out through a 60-300-mesh separating sieve to obtain small powder; 4, the small powder and one or more kinds of high-transparency, medium-transparency and low-transparency dental zirconium oxide powder are mixed uniformly according to different proportions to obtain the coloring zirconium oxide powder. According to the preparing method for the multilayer and multicolor dental ceramics, three to seven kinds of the coloring zirconium oxide powder of the same tone are pressed in a layering and dry pressing mode, pressed in an isostatic pressing mode, and presintered according to the color sequence from dark to light and transparency from small to big to obtain a multilayer and multicolor zirconium oxide blank. The preparing method can prepare dental prosthesis with the transparency and the chromaticity being similar to those of natural teeth.