Manufacturing method of rare earth permanent magnets

The invention provides a manufacturing method of rare earth permanent magnets. The method includes the following processes of firstly, melt-spinning, wherein a magnet raw material is melted and then cast onto a cooling roller to form alloy melt with a roller-attached surface and a free surface, and the alloy melt forms an alloy sheet after being cooled, wherein the temperature difference of the roller-attached surface and the free surface is controlled to be 1-30 DEG C, and the thickness of the alloy sheet is 0.1-0.8 mm; secondly, powder making, wherein the alloy sheet obtained in the first process of melt-spinning is smashed into alloy powder with the average particle size of 10-2000 micrometers, and then the alloy powder forms magnetic powder with the average particle size of 2-8 micrometers, wherein D90/D10 is 3-5. By adopting the method, high-performance magnets can be obtained, the uniformity of magnets is improved, and meanwhile the heavy rare earth content is effectively reduced.