The invention relates to the garment processing field, and specifically relates to a woolen sweater anti-pilling device and method; the anti-pilling device comprises a gas plasma nozzle, a material atomizer and a carrier gas bottle; the gas plasma nozzle comprises an outer electrode and an inner electrode that are separated by an insulation spacing rack; the inner and outer electrodes are connected with a high frequency high voltage power supply; the gas plasma nozzle and the material atomizer are connected via a gas connecting tube; the material atomizer and the carrier gas bottle are connected via a carrier gas tube. The woolen sweater anti-pilling device and method are provided.