Abstract: The 633 nm iodine-stabilized Helium-Neon (He-Ne) laser, utilizing saturable absorption technology, is pivotal in length metrology. Its wavelength within the visible spectrum, combined with a simple and compact structure, and excellent wavelength reproducibility, makes it an extensively used length standard in metrology laboratories. Advancing research on the 633 nm iodine-stabilized He-Ne laser is essential for maintaining China's prominence in length metrology and for supporting the nation's digitalization efforts in metrology. This review discusses the fundamental principles, current research advancements, and the digitization process of the 633 nm He-Ne iodine-stabilized laser. The paper also provides insights into future development trends in this field.