Hard calcium ferrite and manufacturing method thereof

The invention which discloses a hard calcium ferrite and a manufacturing method thereof belongs to the field of hard ferrites. The hard calcium ferrite comprises a main component of CadeltaAsigmaRtauFe12O19, wherein A is at least one element of Sr and Ba, and R is at least one element which is selected from La, Nd, and Pr and must contains La; a soft ferrite component with the composition formulaof WnFemO(n+3m/2), wherein W is one or more of Mn, Co, Zn, and Ni; and a composite additive, wherein the composite additive contains at least an additive with the composition formula of MxBySizO(x+2z+3y/2), and in the composition formula, M is one or more divalent metal elements, such as Sr, Ba, and Ca. The hard ferrite magnet obtained in the invention has a Br of 4200-4700 Gs, a HCJ of 4900-5700Oe, and a squareness ratio (Hk/HCJ) of above 90%, and especially has the Br of 4400-4700 Gs, the HCJ of 5000-5700 Oe, and the squareness ratio of above 95%, and simultaneously the production cost is substantially reduced.