Powder coating material

A method for preparing a thermosetting powder coating material comprises: dispersing and mixing a base resin and a crosslinking agent in a dispersing and/or mixing machine equipped with a decompression device at a temperature in the range of 40 to 200‹C, to form a dispersed mixture, the dispersed mixture optionally containing a solvent and a pigment; optionally eliminating at least a portion of the solvent under reduced pressure; adding water to the dispersed mixture; reducing the pressure and lowering the temperature of the dispersed mixture to a temperature equal to or less than the softening point of the dispersed mixture; and bringing the dispersed mixture into a powder state or a granule state by dispersion force of the dispersing and/or mixing machine. The base resin may be an acrylic varnish comprising a glycidyl methacrylate copolymer, a polyester resin containing hydroxyl groups, epoxy resin or fluoro resin.