The invention discloses a high-Curie-temperature low-loss high-strength ferrite magnetic block and a preparation method thereof and belongs to the technical field of Mn-Zn serial ferrite. Main raw materials include ferric oxide, manganese oxide and zinc oxide, auxiliary raw materials include calcium carbonate, titanium oxide, cobalt oxide, silicon oxide, chromium oxide, niobium oxide, nickle oxide and copper oxide, the ferrite magnetic block is composed of the main raw materials, 55-61mol% of ferric oxide calculated according to Fe2O3, 33-40mol% of manganese oxide calculated according to MnO and 5-10% of zinc oxide calculated according to ZnO, and the adding amount of the auxiliary raw materials relative to the total weight of the main raw materials is 500-3000ppm of CaCO3, 80-3000ppm of TiO2, 50-1200ppm of Co2O3, 20-200ppm of superfine SiO2, 100-1500ppm of Cr2O3, 100-1500ppm of Nb2O5, 600-2000ppm of NiO and 600-2000ppm of CuO. The high-Curie-temperature low-loss high-strength ferrite magnetic block has the advantages that initial magnetic permeability can be lowered to be maintained at 1400+/-25%, power consumption is lower than 550kw/m3 under the condition of 100KHz200mT and at the temperature of 100 DEG C, saturation magnetic flux density at 100 DEG C is larger than 410mT, the Curie temperature is larger than 275 DEG C, and strength of the magnetic block can meet the strength detection standard (F)40N).