The invention relates to the field of powder processing, aims at solving the problems that in the prior art, in the process of processing powder, environment pollution is caused and potential safety hazards exist, and provides a purging device and method for the powder. According to the purging device for the powder, the position of an inlet of a purging tank is detachably connected with a filter screen, and the sizes of powder particles are close after the powder particles pass by the filter screen. An inlet sealing cover is connected to the position of the inlet of the purging tank in a sealed manner, inert gas is injected in a containing cavity of the purging tank through a gas inlet pipe, the powder in the containing cavity is discharged in a powder processing pool through an exhaust pipe, and a complete discharge opening located in the bottom can be opened after purging ends so that the powder which is not discharged can be discharged. The sizes of the powder particles of the purging device for the powder are close, the powder discharge speed can be controlled, meanwhile, the density of the powder is decreased, the powder reacts slowly after being injected in the processing pool, and the safety performance and the environmental protection performance in the purging process are improved.