Disclosed is a passive electromagnetic pen, which includes a pen core, a first iron core, and an iron core holder, wherein a coil is wound outside the first iron core, the first iron core is fixed to an end of the iron core holder close to a pen tip of the pen core, a second iron core, an elastic component, a pressure regulating plate, and a first structure matched with the pressure regulating plate are disposed in the iron core holder sequentially from front to back, and the pen core is configured to pass through a center of the first iron core, and then drive the second iron core to move; and the pressure regulating plate when in rotation is configured to be in surface contact with the first structure by a surface, so as to generate an axial displacement to change an axial displacement of the elastic opponent.