The invention discloses a method for making high-square-degree sintered NdFeB permanent magnets with a
cerium,
titanium,
cobalt and
zirconium compound additive. The method comprises the steps that raw materials are prepared with 27.0% to 29.0% of Nd, 2.5% to 4.0% of Ce, 63.5% to 67.5% of Fe, 1.0% to 1.2% of B, 0.5% to 1.0% of Nb, 1.0% to 3.0% of Co, 0.1% to 0.3% of Zr, 10.5% to 1.0% of A, 0.1% to 0.3% of Cu, and 0.1% to 0.3% of Ti, the raw materials are smelted under the temperature of 1380 DEG with a vacuum induction rapid-hardening
casting strip furnace, smelted
alloy liquid is processed through
electromagnetic stirring to be uniform, and is poured to a rotating water-cooling
copper stick, and the
alloy liquid is rapidly cooled to form
alloy slices with the thickness
ranging from 0.2 mm to 0.5 mm; NdFeB alloy slices are broken into NdFeB alloy particles with the length
ranging from 120 microns to 200 microns with a
hydrogen breaking furnace; the particles are further broken into NdFeB alloy
powder with the length
ranging from 3.0 microns to 4.5 microns by an air-current mill; the
powder is formed in a forming press, and is further densified through isostatic cool pressing; formed initial blanks are sintered, and sintered permanent magnets are finally obtained. With the method for making high-square-degree sintered NdFeB permanent magnets with the
cerium,
titanium,
cobalt and
zirconium compound additive, the squre degree of the permanent magnets can be improved, and the production cost can be greatly reduced.