Electrostatic image developing agent carrier core material as well as preparation method and carrier thereof

The invention relates to an electrostatic image developing agent carrier core material as well as a preparation method and a carrier thereof. The preparation method of the carrier core material comprises the following steps: crushing a mixture of metal oxide and carbon black, used as a raw material, pelleting, forging and roasting, wherein the metal oxide at least comprises elements such as Fe, Mn and Mg; the mass percentage of the carbon black in the raw material is 2-40%. The chemical formula of the carrier core material prepared by using the preparation method is MnxMgyFeZO4 (x is greater than 0 and less than or equal to 1, y is greater than 0 and less than or equal to 1, and z is greater than or equal to 2 and less than 3), the apparent density of the carrier core material is 1.3-2.0g/cm , and the true density of the carrier core material is 2.5-5.5g/cm . The carrier core material has the characteristics of low density and high strength. An electrostatic image developing agent prepared from the carrier core material is small in energy consumption in the developing process, and can ensure good and stable image quality output in long-term use.