The invention discloses an automatic electromagnetic sheet stacking method and system based on a robot. The method comprises the steps: electromagnetic sheets pass through a guiding slot and are purged, so that impurities are removed; the electromagnetic sheets enter a straightening mechanism so as to be straightened, and are then conveyed to a robot grabbing area through a big conveyor line; a sensor detects the number of the electromagnetic sheets; when the sensor detects that the number of the electromagnetic sheets reaches to a preset value, a robot grabs the electromagnetic sheets into a placement plate; the electromagnetic sheets are conveyed after the placement plate is full of the electromagnetic sheets. Through the embodiment of the invention, an automatic electromagnetic sheet stacking process based on the robot is realized, and the robot can grab, place and convey the electromagnetic sheets after the impurities of the electromagnetic sheets are removed, so that the automatic stacking efficiency is improved, and the labor cost is reduced.