The structure and fabrication process of a novel Digital Encoding Grating Ruler (DEGR)were introduced.In this process, the pattern of DEGR is firstly fabricated on a (100) silicon wafer by combining UV lithography and holography lithography with wet etch technique, and then replicated to a hard substrate using polyurethane acrylate which is UV curable. Experimental results show that the process is highly repeatable. The replicated gratings work properly in the ambient temperature ranging from －55℃ to 70℃, and its diffraction efficiency is higher than 90% of the master one. The fabrication precision meets the requirements of the optical sensor, and the signal response accuracy is 100%. Moreover, this process could be used to fabricate other micro-nanometer structures with high precision, complex pattern and poor working environment.