Abstract: The measurement accuracy of nano line widths, a critical nano geometric characteristic parameter, is of paramount importance in fields such as advanced manufacturing. As the scale of nanotechnology continues to shrink, achieving sub-nanometer measurement accuracy presents new challenges. The 26th General Conference on Weights and Measures (CGPM) in 2018 proposed using the silicon 220 lattice spacing as a secondary realization of the meter, providing a novel approach for atomic-level nano line width measurements. In this study, a 22 nm intrinsic silicon lattice line width standard was developed using multi-layer film deposition technology. Employing high-resolution transmission electron microscopy (HRTEM), the silicon lattice constant within the standard was used as a scale for direct nano line width measurement. The measurement uncertainty achieved is better than 1 nm.