The present application provides a method, an apparatus, and a system for forming code. The method includes while a substrate is transferred to an exposure machine, adjusting the substrate to align with an exposure alignment mark on the substrate with the exposure machine; forming a code formation area on the adjusted substrate by controlling the exposure machine; while the substrate formed with the code formation area is transferred to a code formation machine, adjusting the substrate to align the exposure alignment mark on the substrate with the code formation machine; and forming an identification code in the code formation area on the adjusted substrate by controlling the code formation machine.