The invention provides a fabrication process of a high-coercivity Nd-Fe-B rare-earth permanent magnet. A technology of preparing a rare-earth thin film from an ion liquid is applied to fabricate a high-performance magnet, a Rb thin film is grown on a surface of the magnet by the technology, a Rb element plated on the surface of the magnet is diffused to the interior of the magnet by primary high-temperature thermal processing, a rare-earth rich phase is uniformly distributed around the magnet by secondary low-temperature tempering, and meanwhile, unbalanced tissue and internal stress brought by high-temperature processing are eliminated. The intrinsic coercivity of the magnet after being processed by the process can be obviously improved, so that the high-coercivity Nd-Fe-B rare-earth permanent magnet is fabricated. By the process, the production efficiency can be improved, the heavy rare-earth dosage during the fabrication process is reduced, and meanwhile, high coercivity is obtainedunder the condition that residual magnetism and magnetic energy product of the magnet are not reduced.