The invention relates to a preparation method for a mullite infrared radiation multiphase ceramic. The preparation method comprises the following steps: (1) weighing, by weight, 25 parts of Fe2O3, 55parts of MnO2, 10 parts of Co2O3, 10 parts of CuO, 10 parts of Ni2O3 and 50 parts of Cr2O3, and preparing ferrite by using a sol method; (2) weighing, by weight, 20% of ferrite, 75% of mullite and 5%of calcined kaolin, and grinding and uniformly mixing the above raw materials by using an agate mortar to obtain a powder for subsequent usage; (3) adding a binder solution accounting for 3% of the total weight of the powder, carrying out granulation, and then performing aging for 24 to 36 h; (4) subjecting the powder to compaction molding, and then carrying out drying to obtain a ceramic preformbody; and (5) sintering and molding the ceramic preform body so as to obtain the mullite infrared radiation multiphase ceramic. The preparation method of the invention adopts ferrite composite mullitewith high radiation performance and calcined kaolin, so the prepared infrared radiation ceramic has a low thermal expansion coefficient, good thermal shock resistance and high infrared radiation performance.