The invention discloses a HfO2-containing ferromagnetic core manufacturing method, which comprises the following steps of: proportioning 68-75 parts of reduced iron powder by weight, 15-17 parts of oxidized iron powder by weight, 4.2-4.5 parts of MnO by weight, 3.6-4.2 parts of ZnO by weight, 1.7-2.3 parts of modified tree ash by weight, 0.5-0.7 part of nano carbon by weight, 1-3 parts of HfO2 by weight, 2.5-2.7 parts of SiO2 by weight, 3.4-3.8 parts of V2O5 by weight and 2-3 parts of CuO by weight, and then sequentially conducting pre-sintering, primary ball milling, secondary ball milling, molding and sintering to obtain a HfO2-containing ferromagnetic core. The HfO2-containing ferromagnetic core manufacturing method has the advantages that the magnetic core formula is reasonable, the preparation method is simple, the saturation induction density of the manufactured magnetic core is higher, the loss is lower, the temperature resistance is higher, the added modified tree ash and the nano carbon can take a bridge bonding effect among different raw materials, the distribution of the used raw materials is better, the density is high, the crystal boundary resistivity is high, the porosity is low, the grains are large and uniform, the cracks are prevented from occurring during sintering, the texture is compact, the deformation is small, the raw material formula is reasonably improved, the deformation degree is small during sintering, and the magnetic core can be wire-cut, cut, ground and the like.