A technology for double-sided etch and blackening of inch stainless steel ruler includes such steps as cutting off material, cutting off stainless steel workpiece to be processed, cutting off stainless steel workpiece to be blackened, cutting off stainless steel workpiece to be blackened, cutting off stainless steel workpiece to be blackened, cutting off stainless steel workpiece to be blackened,cutting off stainless steel workpiece to be blackened. Deburring leveling, oil removal, wire drawing, double-sided screen printing, drying, double-sided film bonding, photosensitivity, placement in developing bath, plate trimming inspection, pre-etching, etching machine etching, cleaning neutralization drying, blackening, paint spraying, paint scraping, polishing, double-sided film coating, positioning hole through hole, stamping forming, inspection waxing packaging warehousing. Black imperial steel rule scale and numerals of that invention are white, are easy to identify when use, form denseblack oxide film on the surface, can improve the corrosion resistance of the steel rule and meet the requirements of the optical system, and can be printed on two sides for more than one foot, thus bee convenient and quick.