Method for preparing rare earth permanent magnet

Provided is a method for preparing a rare earth permanent magnet, which comprises a blank magnet preparing procedure not comprising a tempering treatment step, a permeating material coating procedure and a heat treatment procedure. The blank magnet preparing procedure not comprising a tempering treatment step refers to performing procedures of compounding-alloy smelting-powder production through pulverization-forming-sintering to manufacture a blank magnet. The permeating material coating procedure comprises procedures of preparing a permeating material powder, preparing the permeating material powder as a coating solution, coating the blank magnet in the coating solution etc. In the present invention, a rare earth intermetallic compound is used as a diffusion material, and the rare earth intermetallic compound has more stable phases and components and is easily pulverizable; and the rare earth intermetallic compound has a wide phasing element range, and the composition of the rare earth intermetallic compound can be adjusted and formed according to requirements of the magnet performance. The present invention can improve boundary characteristics of crystal boundaries and the interaction thereof with main phase grains, and improves the intrinsic coercive field of a sintered neodymium-iron-boron magnet, while the remanence and maximum magnetic energy product are reduced less in quantity.