A preparation method of multilayer-colored dental composite material, characterized in that, it comprises: a) preparing N monochrome composite precursor powders with different colors, N≥3; wherein, the preparation process for each of monochrome composite precursor powder comprises: mixing polymer monomer matrix, inorganic filler, initiator, coloring agent, and milling additive, and milling for 0.5-2 h, then drying to obtain monochrome composite precursor powder; wherein, the weight ratio of the polymer monomer matrix to the inorganic filler is 10:90-90:10, preferably 15:85-30:70, the initiator is 0.1%-1%, preferably 0.2%-0.5% by weight of the polymer monomer matrix, and the coloring agent is 0.01%-0.2%, preferably 0.03%-0.1% by weight, based on the total weight of the polymer monomer matrix and the inorganic filler; b) adding one monochrome composite precursor powder into a dry-pressing mould, and then adding another monochrome composite precursor powder into the dry-pressing mould successively after planishing the previously added powder, until N monochrome composite precursor powders with different colors are all added into the dry-pressing mould; then pre-moulding by dry-pressing at a pressure of 3-20 MPa to obtain a pre-moulding green body of multilayer-colored composite material; or b') performing a first pre-moulding by dry-pressing at a pressure of 3-20 MPa on N monochrome composite material precursor powders, respectively, to obtain N monochrome pre-moulding green bodies; then adding all of the N monochrome pre-moulding green bodies into the mould successively, and performing a second pre-moulding by dry-pressing at the pressure of 3-20 MPa to obtain a pre-moulding green body of multilayer-colored composite material; c) pressurizing and heating the pre-moulding green body of multilayer-colored composite material prepared in step b) or b') to obtain multilayer-colored dental composite material, wherein, the pressurizing and heating is performed at a temperature of 100-200 °C, preferably 120-180 °C, more preferably 130-150 °C for 0.5-3 h, preferably 1-1.5 h. a) preparing N monochrome composite precursor powders with different colors, N≥3; wherein, the preparation process for each of monochrome composite precursor powder comprises: mixing polymer monomer matrix, inorganic filler, initiator, coloring agent, and milling additive, and milling for 0.5-2 h, then drying to obtain monochrome composite precursor powder; wherein, the weight ratio of the polymer monomer matrix to the inorganic filler is 10:90-90:10, preferably 15:85-30:70, the initiator is 0.1%-1%, preferably 0.2%-0.5% by weight of the polymer monomer matrix, and the coloring agent is 0.01%-0.2%, preferably 0.03%-0.1% by weight, based on the total weight of the polymer monomer matrix and the inorganic filler; b) adding one monochrome composite precursor powder into a dry-pressing mould, and then adding another monochrome composite precursor powder into the dry-pressing mould successively after planishing the previously added powder, until N monochrome composite precursor powders with different colors are all added into the dry-pressing mould; then pre-moulding by dry-pressing at a pressure of 3-20 MPa to obtain a pre-moulding green body of multilayer-colored composite material; or b') performing a first pre-moulding by dry-pressing at a pressure of 3-20 MPa on N monochrome composite material precursor powders, respectively, to obtain N monochrome pre-moulding green bodies; then adding all of the N monochrome pre-moulding green bodies into the mould successively, and performing a second pre-moulding by dry-pressing at the pressure of 3-20 MPa to obtain a pre-moulding green body of multilayer-colored composite material; c) pressurizing and heating the pre-moulding green body of multilayer-colored composite material prepared in step b) or b') to obtain multilayer-colored dental composite material, wherein, the pressurizing and heating is performed at a temperature of 100-200 °C, preferably 120-180 °C, more preferably 130-150 °C for 0.5-3 h, preferably 1-1.5 h.