The characteristics of the desorption process of the hydrogenation disproportionation product of NdFeB alloy were investigated. Nd Fe B alloy was melted in a vacuum mild frequency induction furnace. The sample was prepared by a hydrogenation disproportionation desorption recombination process. The mechanism of the recombination Nd 2Fe 14 B type hard magnetic material by a desorption of hydrogenation disproportionation product of NdFeB alloy was established by the comparison of the microstructures, X-ray diffraction patterns and magnetic properties.