Abstract: In recent years, Nanoimprint Lithography (NIL) has shown broad application potential in optics, biology, and other fields. As a high-resolution and low-cost technique for large-area micro/nanostructure patterning, it provides a valuable tool for microfabrication. This paper summarizes NIL’s development history and technical classification, with a focus on its emerging uses in micro/nano-optical devices and biosensing. Currently, NIL serves as a key mass-production tool for micro/nano-optical devices, including AR subwavelength waveguides, microlens arrays and mid-infrared devices. In biodetection, nano-optical structures fabricated via NIL can enhance signals, thereby boosting the detection sensitivity of biomolecules. As a counterpart to traditional lithography, NIL will increasingly excel in the high-precision, high-throughput and low-cost mass production of semiconductors, optical devices and biomolecular detection systems.