The invention provides a method for improving corrosion resistance and coercive force of a sintered neodymium-iron-boron magnet, and belongs to the technical field of magnetic materials. The performance of the magnet is improved by adopting a method that the sintered neodymium-iron-boron magnet is soaked in a liquid gallium solution at a certain temperature. The method particularly comprises the steps that firstly a pretreated sintered neodymium-iron-boron magnet and moderate solid gallium are taken to be placed in a crucible, then the crucible is placed in a vacuum thermal treatment furnace to be heated, wherein the temperature is 400-600 DEG C, the time is 0.5-1 hour, then after the thermal treatment is completed, the crucible is taken out and heated in the air until the temperature is 30 DEG C, then the magnet is taken out from the melted gallium. The corrosion resistance and coercive force of the treated magnet are improved.