Abstract: A system for forming a security pattern by magnetic and optical fields includes: a printing substrate having an inducible ink pattern printed on its surface; and at least one set of security pattern forming units through which the printing substrate passes sequentially. Each set of security pattern forming units includes: a magnetic field and a light source each acting on a surface of the printing substrate, such that after the printing substrate passes through the security pattern forming unit, an inducible ink pattern on the surface thereof exhibits the effect of the dual function of the optical field and the magnetic field.