Method for improving magnet coercive force

The invention provides a method for improving magnet coercive force. The method comprises the processes that a coating process is conducted, the surface of a magnet is coated with a coating material, and drying is conducted; an osmosis process is conducted, heat treatment is conducted on the magnet obtained from the coating process. The coating material comprises metal calcium particles and particles of materials containing rare-earth elements; the rare-earth elements are selected from at least one of praseodymium, neodymium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutecium. According to the method for improving the magnet coercive force, the coercive force of a permanent magnet material can be greatly improved, and remanence and magnetic energy product are reduced a little. In addition, by means of the method for improving the magnet coercive force, the dose of the rare-earth elements can be greatly reduced, and the production cost is reduced.