The invention discloses a large-area super-resolution photoetching device and belongs to the technical field of super-resolution photoetching equipment. The device comprises a vibration isolation foundation, an active vibration isolation platform, a main base plate, an ultraviolet exposure light source, a gap detection system, an alignment module, a super-resolution photoetching lens module, a workbench module, a laser interferometry system, an ultraprecise environmental control system and a control system. Through an interference technology, the device achieves online gap detection of nanometer level precision; through a precise levelling and gap control technology, the gap photoetching function at tens of nanometer levels is achieved; through a local air control technology of a sheet bearing platform, the large-area super-resolution stepping photoetching function is achieved.